Positioning a wearable device for data collection

ABSTRACT

Wearable devices are described herein including at least two photodetectors and a mount configured to mount the at least two photodetectors to an external surface of a wearer. The at least two photodetectors are configured to detect alignment between the wearable device and a target on or in the body of the wearer (e.g., to detect the location of vasculature within the body of the wearer relative to the at least two photodetectors). Alignment of the at least two photodetectors relative to the target could enable detection of one or more physiological properties of the wearer. For example, the wearable device could include a sensor configured to detect a property of the target when the sensor is above the target, and alignment of the target relative to the at least two photodetectors could include the sensor being located above the target.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

Certain medical states or conditions of a human body can be detectedusing sensors disposed outside of the human body (e.g., disposedagainst, on, or otherwise proximate an external body surface of thehuman body). Some medical states or conditions can change slowly, occurrarely, or otherwise indicate that monitoring of the human body over anextended period of time is preferred. A sensor disposed in a wearabledevice can enable long-term monitoring of a medical state or conditionof the body of a wearer while allowing the wearer to perform activitiesof daily living, to travel, to commute, or to engage in other activitieswith minimal interruption. Such monitoring by a wearable device could beperformed preventatively, e.g., to monitor an otherwise healthy wearer'shealth state over time to enable early detection of an adverse medicalcondition, to develop data describing a ‘healthy’ baseline state of thewearer, or to enable other applications. Medical states or conditions ofa human body monitored by such a wearable device can include pulse rate,blood oxygenation, activity level, blood pressure, galvanic skinresponse, or other information about the body of a wearer.

SUMMARY

Some embodiments of the present disclosure provide a wearable deviceincluding: (i) at least two photodetectors, wherein the at least twophotodetectors are configured to detect alignment of a target relativeto the at least two photodetectors; (ii) a mount configured to mount theat least two photodetectors to an external body surface proximate to thetarget; and (iii) a controller configured to operate the at least twophotodetectors to detect alignment of the target relative to the atleast two photodetectors.

Some embodiments of the present disclosure provide a wearable deviceincluding: (i) at least two light emitters, wherein the at least twolight emitters are configured to illuminate a target; (ii) at least onephotodetector, wherein the at least one photodetector is configured todetect alignment of a target relative to the at least one photodetectorby detecting light emitted from the target in response to illuminationby the at least two light emitters; (iii) a mount configured to mountthe at least two light emitters and at least one photodetector to anexternal body surface proximate to the target; and (iv) a controllerconfigured to operate the at least two light emitters and at least onephotodetector to detect alignment of the target relative to the at leastone photodetector.

Some embodiments of the present disclosure provide a method thatinvolves mounting a wearable device to an external body surface. Thewearable device includes (i) at least one light emitter, (ii) at leastone photodetector, (iii) a mount configured to mount the at least onelight emitter and at least one photodetector to an external body surfaceproximate to a target, and (iv) a controller configured to operate theat least one light emitter and at least one two photodetector. Themethod further involves detecting, by the controller, an alignment ofthe at least one light emitter and at least one photodetector relativeto the target.

These as well as other aspects, advantages, and alternatives, willbecome apparent to those of ordinary skill in the art by reading thefollowing detailed description, with reference where appropriate to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view of an example wearable device while ona human wrist.

FIG. 1B is a cross-sectional view of an example wearable device while ona human wrist and while two sensors of the example wearable device arealigned with a target in the wrist.

FIG. 1C is a cross-sectional view of an example wearable device while ona human wrist and while a particular sensor of the example wearabledevice is aligned with a target in the wrist.

FIG. 1D is a cross-sectional view of an example wearable device while ona human wrist and while a particular sensor of the example wearabledevice is aligned with a target in the wrist.

FIG. 1E is side partial cross-sectional view of an example wearabledevice while on a human wrist.

FIG. 1F is a cross-sectional view of an example wearable device while ona human wrist and while a particular sensor of the example wearabledevice is aligned with a target in the wrist.

FIG. 1G is a cross-sectional view of an example wearable device while ona human wrist and while a sensor of the example wearable device isaligned with a target in the wrist.

FIG. 1H is a cross-sectional view of an example wearable device while ona human wrist and while sensors of the example wearable device arealigned with a target in the wrist.

FIG. 2A is a cross-sectional view of an example wearable device while ona human wrist.

FIG. 2B is a cross-sectional view of the example wearable deviceillustrated in FIG. 2A while on a human wrist and while two sensors ofthe example wearable device are aligned with a target in the wrist.

FIG. 3A is side partial cross-sectional view of an example wearabledevice while on a human wrist.

FIG. 3B is a top view of the example wearable device illustrated in FIG.3A.

FIG. 3C is a cross-sectional view of the example wearable deviceillustrated in FIG. 3A while on a human wrist and while a particularsensor of the example wearable device is aligned with a target in thewrist.

FIG. 3D is a top view of the example wearable device illustrated in FIG.3C.

FIG. 4 is a perspective view of an example wearable device.

FIG. 5A is a perspective top view of an example wrist-mounted device,when mounted on a wearer's wrist.

FIG. 5B is a perspective bottom view of an example wrist-mounted deviceshown in FIG. 5A, when mounted on a wearer's wrist.

FIG. 6 is a block diagram of an example system that includes a pluralityof wearable devices in communication with a server.

FIG. 7 is a functional block diagram of an example device.

FIG. 8 is a flowchart of an example method.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying figures, which form a part hereof. In the figures, similarsymbols typically identify similar components, unless context dictatesotherwise. The illustrative embodiments described in the detaileddescription, figures, and claims are not meant to be limiting. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the scope of the subject matter presented herein. It willbe readily understood that the aspects of the present disclosure, asgenerally described herein, and illustrated in the figures, can bearranged, substituted, combined, separated, and designed in a widevariety of different configurations, all of which are explicitlycontemplated herein.

Further, while embodiments disclosed herein make reference to use on orin conjunction with a living human body, it is contemplated that thedisclosed methods, systems and devices may be used in any environmentwhere the operation of two or more sensors to locate the relativepositioning of a target is desired. The environment may be any living ornon-living body or a portion thereof, a gel, an emulsion, a fluidconduit, a fluid reservoir, etc. For example, one of skill in the artwill recognize that the embodiments disclosed herein may be used tosense a target (e.g., a fluid conduit, pipe, or tube) within amanufactured device or industrial environment or work piece.

I. Overview

A wearable device may be configured to perform a variety of differentfunctions and/or applications. In some examples, a wearable device isconfigured to measure one or more physiological parameters of thewearer. Measuring one or more physiological parameters of the wearercould include interacting with (e.g., receiving light from,illuminating, detecting a property of) a specific target within the bodyof the wearer. For example, detecting the concentration of an analyte inthe bloodstream of the wearer could include illuminating and detectinglight received from a portion of subsurface vasculature (e.g., a vein orartery) beneath the skin of the wearer. Other functions or applicationsof a wearable device (e.g., delivery of haptic sensations to the wearer,emission of energy to cause a change in one or more analytes in theblood of the wearer) could also be related to a specific target withinthe body of the wearer.

Sensors or other components of a wearable device could be configured todetect the location of such specific targets relative to elements of thewearable device (i.e., to detect the alignment of the target relative tothe elements of the wearable device).

The specific target could comprise a variety of elements of the body ofa wearer. The target could be a portion of subsurface vasculature (e.g.,a vein or artery), a nerve, a muscle, a bone, or some other element ofthe anatomy of the wearer. In some examples, the target could be animplanted device or object. For example, the target could be animplanted polymer chip configured to have a changing color related tothe concentration of an analyte (e.g., glucose) in the environment ofthe polymer chip. The location of the target relative to the wearabledevice could include detecting a property of the target that isdifferent from neighboring regions of the body of the wearer. Forexample, the target could be a vein and the wearable device could detectthe color of light received from an external body surface to locate thevein beneath the external body surface. Detected properties of targetscould include color, fluorescence intensity, fluorescence absorptionspectrum, fluorescence emission spectrum, degree and/or orientation ofpolarization of reflected, emitted, or scattered light, light absorptionspectrum, acoustical absorption spectrum, acoustical reflectivity,radiopacity, RF absorption spectrum, or other properties and/or featuresof the target.

The location and/or alignment of the target relative to the wearabledevice could be detected using one or more sensors configured to detectone or more properties of the target. For example, the wearable devicecould be configured to be mounted to a wrist of the wearer and couldinclude two color sensors configured to detect the alignment of thewearable device relative to a vein in the wrist of the wearer. The colorsensors could be separated by a distance related to the width of thevein and in a direction perpendicular to the direction of the vein. Assuch, the alignment of the vein between the color sensors could bedetected by detecting that the output of the color sensors issubstantially equal (i.e., that the vein is equidistant to both of thetwo sensors). In some examples, a plurality of sensors could be providedto detect the alignment of the target relative to the wearable device.The sensors of the plurality of sensors could include a single type ofsensor or a plurality of sensor types. The plurality of sensors couldinclude temperature sensors, energy sensors, electromagnetic sensors,light sensors, chemical sensors, acoustical sensors, infrared sensors,ultraviolet sensors, or other types of sensors. For example, theplurality of sensors could include photodetectors (e.g., lightdetectors, color detectors, polarity detectors, infrared detectors,ultraviolet detectors, cameras). In some examples, one or more of theplurality of sensors could include energy emitters (e.g., lightemitters, heaters, acoustical transducers) configured to enabledetection of some property of the environment of a sensor byilluminating, heating, or otherwise introducing an energy to theenvironment of the sensor.

Additionally or alternatively, the location and/or alignment of thetarget relative to the wearable device could be detected using one ormore light emitters configured to emit light to illuminate the targetand at least one photodetector configured to detect light emitted fromthe target in response to the illumination. For example, the wearabledevice could be configured to be mounted to a wrist of the wearer andcould include two or more light emitters configured to emit light intorespective regions of the wrist of the wearer (e.g., regions proximateto respective light emitters). Further, light emitted by the lightemitters is preferentially reflected, refracted, or otherwise scatteredby the target (e.g., by blood in a portion of subsurface vasculature, bya wall of a portion of subsurface vasculature) relative to otherelements in the environment of the target (e.g., skin, connectivetissue). The light emitters could be operated to emit respective amountsof light over time (e.g., pulses of illumination, alternating betweenindividual light emitters and/or groups thereof between differentperiods of time) such that the alignment of the target relative to thelight emitters and photodetector could be detected by detecting aproximity between the target and individual plight emitters based on alevel of light received by the photodetector during respective periodsof time corresponding to periods of tiem during which respective lightemitters are emitting light.

The wearable device could include a plurality of sensor and/or lightemitters that could be arranged according to an application of thewearable device. For example, the sensors and/or light emitters could bearranged in a linear array. A linear array of sensors and/or lightemitters could be especially useful in applications wherein the wearabledevice is configured to be mounted around a wrist or other protrudinganatomy of a wearer. The alignment of such a wearable device with atarget (e.g., a vein, nerve, bone, or other anatomical element disposedlargely parallel to the direction of the protruding anatomy) could berelated to a rotation of the wearable device about the protrudinganatomy (e.g., an angle measured about the center of the protrudinganatomy between an element of the wearable device and the target in theprotruding anatomy) such that a linear array of sensors and/or lightemitters arranged along an external surface of the protruding anatomyand perpendicular to the direction of the protruding anatomy could beused to measure the alignment of (e.g., angle between) the wearabledevice and the target. Other one- and two-dimensional patterns (e.g.,rectangular and hexagonal grids) of sensors and/or light emitters areanticipated to enable the detection of the location and/or alignment ofa variety of targets according to a variety of applications.

In some examples, the wearable device could detect alignment relative toa target by detecting the location of (and/or alignment relative to)some other alignment feature. In some examples, the alignment featurecould have a known and/or specified location or orientation relative tothe target, such that detection of the location of the alignment featurecould be used to determine the location of the target. For example, thealignment feature could be a tendon in the wrist of a wearer that has aknown spatial relationship with a target artery in the wrist. Thealignment and/or location of the alignment feature relative to thewearable device could be in some sense easier to detect and/or able tobe detected more quickly, more precisely, and/or more accurately by thewearable device than the location of the target relative to the wearabledevice; as such, determination of the location of the alignment featurecould allow a quicker, more precise, more accurate, or in some other waysuperior determination of the location and/or alignment of the targetthan a direct determination of the location and/or alignment of thetarget. In some examples, the alignment feature could be an artificialfeature (e.g., a tattoo, a temporary tattoo, a piercing, a label adheredto skin, an implanted marker or other device) having a known locationand/or orientation relative to a target. For example, a tattoocomprising a fluorescent dye could be applied to an external bodysurface above a target (e.g., a nerve). Note that the target couldsimply be a region of tissue of a wearer having known properties (e.g.,a known baseline, a known pattern of innervation, etc.) according to anapplication. The location of such targets could be detected based onalignment features.

In some examples, detection of the alignment of a target relative to thewearable device could enable the detection of one or more properties ofthe target and/or of the body of the wearer. For example, a sensor ofthe wearable device could be configured to detect the concentration ofan analyte in the blood when the sensor is aligned with a portion ofvasculature of the wearer. Detection of the alignment of the portion ofvasculature with the wearable device (i.e., with the sensor) could beused to operate the sensor to detect the concentration of the analyte inthe blood in the portion of vasculature. Additionally or alternatively,the sensors employed to detect the alignment of the target couldadditionally be configured to detect one or more properties of thetarget and/or of the body of the wearer. The presence of two or moresuch sensors could enable detection of the one or more properties acrossa wider variety of relative alignments of the target with the wearabledevice. In some examples, detection of the alignment of a targetrelative to the wearable device could enable the modification of someelement of the body of the wearer by the wearable device. For example,an energy emitter (e.g., a light source, an RF emitter, an acoustictransducer) of the wearable device could be configured to modify (e.g.,heat, denature, destroy, cause a change in state of) an analyte in theblood when the energy emitter is aligned with a portion of vasculatureof the wearer. Detection of the alignment of the portion of vasculaturewith the wearable device (i.e., with the energy emitter) could be usedto operate the energy emitter to modify the analyte in the blood in theportion of vasculature. Other applications of detection of the locationand/or alignment of a target relative to a wearable device areanticipated.

Detection of the alignment and/or location of a target relative to thewearable device could be used to effect a change in the alignmentbetween the target and the wearable device. In some examples, thewearable device could be configured to indicate the level, direction,angle, or some other property of the detected alignment (e.g., byproviding a tone, a vibration, a visual indication) such that the wearercould adjust the wearable device to align the wearable device with thetarget (e.g., by rotating the wearable device about a wrist to which thewearable device is mounted). In some examples, the wearable device couldinclude an actuator (e.g., a motor, a solenoid) and the actuator couldbe operated to adjust the alignment of an element or elements (e.g., asensor, an energy emitter) of the wearable device with the target.Adjustment of the alignment of the wearable device could beindicated/effected periodically or in response to some condition (e.g.,a determination that the alignment between the wearable device and thetarget had decreased below some threshold level).

In some examples, the wearable device may include a user interface thatis configured to provide user-discernible indications (e.g., visual,audible, and/or tactile indications) of information sensed by sensors ofthe wearable device, progress or other information related to a functionof the device, or other information. In some examples, the userinterface could additionally provide a means for one or more settings ofthe wearable device (e.g., a sampling rate, a user information privacysetting, a user's credentials to access a service) to be specified by awearer according to the wearer's preferences. In some examples, thewearable device may include a wireless communication interface that cantransmit/receive data to/from an external device, for example, usingBluetooth, ZigBee, WiFi, and/or some other wireless communicationprotocol. The data transmitted by the wireless communication interfacemay include data indicative of one or more physiological parametersmeasured by the device, the alignment of a target relative to thedevice, a blood oxygenation level, or the concentration of an analyte inthe blood of the wearer. The wireless communications interface couldadditionally or alternatively be configured to receive data from anexternal system (e.g., parameters relating to the operation of an energyemitter configured to emit energy into blood of the wearer to effect achange in some analyte in the blood).

II. Example Wearable Devices

Wearable devices as described herein can be configured to be mounted toan external body surface of a wearer and to enable a variety ofapplications and functions including the detection of alignment betweena target on or within the body of the wearer and one or more componentsof the wearable devices. Two or more sensors (e.g., photodetectors)and/or two or more light emitters could be used to detect alignment of atarget on or within the body of the wearer when the wearable device ismounted to the external body surface. Alignment could include the targethaving a relative location and/or orientation relative to elements ofthe wearable device (e.g., the at least two sensors, the at least twolight emitters) in one or more dimensions. Such wearable devices couldenable a variety of applications, including measuring physiologicalinformation about a wearer, indicating such measured physiologicalinformation or other information to the wearer (e.g., using a vibrator,a screen, a beeper), or other functions. The wearable device could beoperated relative to a target alignment detected using the at least twosensors.

The two or more sensors and/or two or more light emitters being used todetect the alignment of a target could include detecting a location,orientation, or some other information about the configuration of thetarget relative to the location, orientation, and/or configuration ofthe two or more sensors, two or more light emitters, and/or otherelements of a wearable device. In some examples, detecting alignment ofthe target could include detecting and/or generating a continuousvariable related to the alignment of the target. For example, the two ormore sensors and/or two or more light emitters could be configured todetect a distance and/or direction between the location of the targetand the location of an element of the wearable device.

In some examples, detecting alignment of the target could includedetermining categorical and/or qualitative information related to thealignment of the target. For example, the two or more sensors and/or twoor more light emitters could be configured to generate information todetermine a binary variable related to whether the target is “aligned”(e.g., location within and/or passing through a specified regionrelative to the wearable device). Alignment of a target could includethe target being within and/or partially occupying a specified regionrelative to the two or more sensors, two or more light emitters, and/orother elements of the wearable device. For example, alignment couldinclude the target occupying and/or passing through a region directlybelow one of the two or more sensors and/or two or more light emitters,a region midway between two sensors or two light emitters, or some otherspecified region or regions. Alignment of a target could include thetarget being within and/or partially occupying one of more than onespecified region. For example, alignment could include the targetoccupying and/or passing through a region directly below any particularsensor and/or light emitter in an array of two or more sensors and/ortwo or more light emitters.

FIG. 1A is a partial cross-sectional view through a human wrist 105 aillustrating an example wearable device 100 a when mounted to the humanwrist 105 a. The wearable device 100 a includes a housing 110 a (e.g., awater-resistant and/or water-proof housing) configured to containelectronic components and to be mounted to an external body surface of awearer by a mount 120 a. The mount 120 a can be a band configured toenclose the wrist 105 a and to position first 130 b and second 140 asensors in the housing 110 a proximate to a target 107 a (i.e., aportion of subsurface vasculature) in the wrist 105 a. The wearabledevice 100 a includes additional elements that are not shown, e.g.,electronics configured to operate the first 130 a and second 140 asensors and to enable applications and/or functions of the wearabledevice 100 a, a rechargeable battery configured to power the wearabledevice 100 a, or other components. Components of the wearable device 100a could be disposed on or within the housing 110 a, the mount 120 a, orsome other elements of the wearable device 100 a (not shown); e.g., asecond housing.

The housing 110 a could be configured to be water-resistant and/orwater-proof. That is, the housing 110 a could be configured to includesealants, adhesives, gaskets, welds, press-fitted seams, and/or otherjoints such that the housing 110 a was resistant to water entering aninternal volume or volumes of the housing 110 a when the housing 110 ais exposed to water. The housing 110 a could further be water-proof,i.e., resistant to water entering an internal volume or volumes of thehousing 110 a when the housing 110 a is submerged in water. For example,the housing 110 a could be water-proof to a depth of 1 meter, i.e.,configured to resist water entering an internal volume or volumes of thehousing 110 a when the housing 110 a is submerged to a depth of 1 meter.Further, the interface between the housing 110 a and other elements ofthe wearable device 100 a (e.g., elements of a sensor, buttons, userinterface elements, electrical contacts, sensors 130 a, 140 a)protruding from, embedded in the surface of, or otherwise interruptingthe material of the housing 110 a could be configured such that thecombination of the housing 110 a and the other elements of the wearabledevice 100 a is water-resistant and/or water-proof.

The sensors 130 a, 140 a could include one or more photodetectors (e.g.,light sensors, IR sensors, UV sensors), electric field sensors, magneticfield sensors, electromagnetic energy sensors, temperature sensors,electric current sensors, electric potential sensor, acoustical sensors,force transducers, or some other sensors or combination(s) of sensors.The sensors 130 a, 140 a could include one or more light emitters, IRemitters, electromagnetic energy emitters, heaters, vibrators,acoustical energy emitters, force transducers, or some other energyemitters. One or both of the sensors 130 a, 140 a could be configured tooperate in direct contact with an external body surface of the wearer(e.g., configured to include a heat- or electricity-conducting probe orother element in physical contact with the skin of the wearer tofacilitate detection of one or more properties of the body of thewearer). Additionally or alternatively, one or both of the sensors 130a, 140 a could be configured to indirectly (i.e., without directlycontacting an external body surface of the wearer) detect informationabout the target 107 a or some other element or elements of the wearer'sbody (e.g., to detect electromagnetic, optical, acoustical, or otherfields and/or energies emitted, reflected, scattered and/or generated byelements of the wearer's body and received by the sensors 130 a, 140 a).

The sensors 130 a, 140 a could interact with and/or detect one or moreproperties of specific elements or components of the body of the wearer(e.g., the target 107 a). In some examples, one or both of the sensors130 a, 140 a could act to illuminate or otherwise direct energy towardelements in the body of the wearer (e.g., the target 107 a) and coulddetect a light or other energy emitted by, reflected by, scattered by,or otherwise received from the elements in response to the illuminationand/or direction of energy toward the elements. For example, one or bothof the sensors 130 a, 140 a could be configured to illuminate afluorophore, chromophore, or other optic chemical, moiety, analyte, orother element of the body of the wearer and to detect light emitted,scattered, reflected, or otherwise received from the element of the bodyof the wearer in response to the illumination. One or more properties ofthe illumination and/or of the detected light could be used to determineone or more properties of the body of the wearer. For example, a colorof light received by a sensor could be used to determine whether thetarget 107 a (a portion of subsurface vasculature) is in a specifieddirection (i.e., a direction of light sensitivity of the sensor) bycomparing the color of the received light to an expected color of thetarget 107 a (e.g., a blue color of a vein). In another example, asensor could be configured to emit a pulse of acoustic energy and todetect a time delay of acoustic energy reflected by the target 107 a;the detected time delay could be related to a distance between thesensor and the target 107 a.

In some examples, the body of the wearer (e.g., the target 107 a, i.e.,subsurface vasculature) could include artificial or other contrastagents (e.g., fluorophores, fluorescent nanodiamonds, chromophores,acoustic particles, magnetic particles) functionalized or otherwiseconfigured to enable the detection of alignment of the target 107 aand/or of one or more properties of the body of the wearer using sensors(e.g., 130 a, 140 a) of the wearable device 100 a. For example, acontrast agent including a fluorophore could be configured toselectively bind to an analyte of interest in the blood of the wearer,and a sensor (e.g., 130 a, 140 a) could be operated to determine topresence, location, binding state, or other properties of the contrastagent in the blood. The determined one or more properties of thecontrast agent could be used to determine an alignment of the target 107a relative to the sensor and/or other component(s) of the wearabledevice 100 a. Other contrast agents, properties of the body of thewearer, and configurations and method of operation of the wearabledevice 100 a are anticipated.

As illustrated in FIG. 1A, the target 107 a is located beneath thehousing 110 a, at a location between the first 130 a and second 140 asensors. In some embodiments, the first 130 a and second 140 a sensorscould be configured to determine the location of the target 107 arelative to the sensors 130 a, 140 a, the housing 110 a, or some otherelement(s) of the wearable device 100 a. That is, detecting alignment ofthe target 107 a could include operating the sensors 130 a, 140 a, todetect the location, orientation, or some other information about thedisposition of the target 107 a. In some embodiments, the illustratedlocation of the target 107 a relative to the sensors 130 a, 140 a,housing 110 a, and/or other components of the wearable device 100 acould be one of one or more specified locations, such that the target107 a is aligned relative to element(s) of the wearable device 100 a.Thus, the sensors 130 a, 140 a could be operated as described above todetect the location, orientation, or some other information about thetarget 107 a and a determination that the target 107 a is aligned couldbe made based on such detected information. Additionally oralternatively, the sensors 130 a, 140 a could be configured to detectsome categorical and/or qualitative information about the alignment ofthe target 107 a. For example, the sensors 130 a, 140 a could beconfigured to detect that the alignment of the target 107 a correspondsto one of a discrete set of states, e.g., ‘aligned,’ ‘nearly aligned,’‘not aligned,’ ‘not aligned in the direction of the first sensor 130 a,’‘not aligned in the direction of the second sensor 140 a,’ etc. That is,in some examples the disposition of the target 107 a relative tocomponent(s) of the wearable device 100 a could be such that the target107 a is not aligned.

FIG. 1B is a partial cross-sectional view through a human wrist 105 billustrating an example wearable device 100 b when mounted to the humanwrist 105 b. The wearable device 100 b could be configured similarly tothe wearable device 100 a of FIG. 1A, and includes a housing 110 b(e.g., a water-resistant and/or water-proof housing) configured tocontain electronic components and to be mounted to an external bodysurface of a wearer by a mount 120 b. The mount 120 b can be a bandconfigured to enclose the wrist 105 b and to position first 140 b andsecond 140 b sensors in the housing 110 b proximate to a target 107 b(i.e., a portion of subsurface vasculature) in the wrist 105 b.

As illustrated in FIG. 1B, the target 107 b is located beneath thehousing 110 b, at a location midway between the first 130 b and second140 b sensors. In some embodiments, the first 130 b and second 140 bsensors could be configured to determine the location of the target 107b relative to the sensors 130 b, 140 b, the housing 110 b, or some otherelement(s) of the wearable device 100 a. That is, detecting alignment ofthe target 107 b could include operating the sensors 130 b, 140 b, todetect the location, orientation, or some other information about thedisposition of the target 107 b. In some embodiments, the illustratedlocation of the target 107 b relative to the sensors 130 b, 140 b,housing 110 b, and/or other components of the wearable device 100 bcould be one of one or more specified locations, such that the target107 b is aligned relative to element(s) of the wearable device 100 b.Thus, the sensors 130 a, 140 a could be operated as described above todetect the location, orientation, or some other information about thetarget 107 b and a determination that the target 107 b is aligned couldbe made based on such detected information. Additionally oralternatively, the sensors 130 b, 140 b could be configured to detectsome categorical and/or qualitative information about the alignment ofthe target 107 b. For example, the sensors 130 b, 140 b could beconfigured to detect that the alignment of the target 107 b correspondsto one of a discrete set of states, e.g., ‘aligned,’ ‘nearly aligned,’‘not aligned,’ ‘not aligned in the direction of the first sensor 130b,’‘not aligned in the direction of the second sensor 140 b,’ etc. Forexample, the sensors 130 b, 140 b could determine that the target 107 bis aligned based on a property detected by the sensors 130 b, 140 b(e.g., a reflected light intensity, an echo signal latency) beingsubstantially equal.

FIG. 1C is a partial cross-sectional view through a human wrist 105 cillustrating an example wearable device 100 c when mounted to the humanwrist 105 c. The wearable device 100 c could be configured similarly tothe wearable devices 100 a, 100 b of FIGS. 1A and 1B, and includes ahousing 110 c (e.g., a water-resistant and/or water-proof housing)configured to contain electronic components and to be mounted to anexternal body surface of a wearer by a mount 120 c. The mount 120 c canbe a band configured to enclose the wrist 105 c and to position first140 c and second 140 c sensors in the housing 110 c proximate to atarget 107 c (i.e., a portion of subsurface vasculature) in the wrist105 c.

As illustrated in FIG. 1C, the target 107 c is located beneath thehousing 110 c, at a location beneath the second 140 c sensor. In someembodiments, the first 130 c and second 140 c sensors could beconfigured to determine the location of the target 107 c relative to thesensors 130 c, 140 c, the housing 110 c, or some other element(s) of thewearable device 100 c. That is, detecting alignment of the target 107 ccould include operating the sensors 130 c, 140 c, to detect thelocation, orientation, or some other information about the dispositionof the target 107 c. In some embodiments, the illustrated location ofthe target 107 c relative to the sensors 130 c, 140 c, housing 110 c,and/or other components of the wearable device 100 c could be one of oneor more specified locations, such that the target 107 c is alignedrelative to element(s) of the wearable device 100 c. Additionally oralternatively, the target 107 c being located beneath the first sensor130 c could be one of one or more specified alignment locations. Thus,the sensors 130 c, 140 c could be operated as described above to detectthe location, orientation, or some other information about the target107 c and a determination that the target 107 c is aligned could be madebased on such detected information. Additionally or alternatively, thesensors 130 c, 140 c could be configured to detect some categoricaland/or qualitative information about the alignment of the target 107 c.For example, the sensors 130 c, 140 c could be configured to detect thatthe alignment of the target 107 c corresponds to one of a discrete setof states, e.g., ‘aligned,’ ‘aligned with the first sensor 130 c,’‘aligned with the second sensor 140 c,’ ‘nearly aligned,’ ‘not aligned,’‘not aligned in an upward direction,’ ‘not aligned in a downwarddirection,’ etc. In some examples, the sensors 130 c, 140 c coulddetermine that the target 107 c is aligned based on a property detectedby the sensors 130 b, 140 c (e.g., a reflected light intensity, an echosignal latency) being substantially equal to some minimal or maximalvalue.

In some examples, one or more sensors of a wearable device as describedherein could be configured to detect some physiological or otherproperty of the wearer in addition to detecting the alignment of atarget on or within the body of the wearer. For example, the secondsensor 140 c of the wearable device 100 c illustrated in FIG. 1C couldbe configured to detect a physiological or other property of the wearerand/or of the target 107 c (e.g., a blood flow rate, a pulse rate, ablood oxygenation, a blood temperature, a concentration of an analyte inblood) when the second sensor 140 c is aligned with (e.g., disposedabove) the target 107 c. Further operation of the second sensor 140 c todetect the physiological property could be performed in response to adetermination (e.g., using the first 130 c and/or second 140 c sensors)that the target 107 c is aligned with the second sensor 140 c.Additionally or alternatively, operation of the second sensor 140 c todetect the physiological property could be related to the detectedalignment (e.g., detected using the first 130 c and second 140 csensors). For example, a mapping or other calculation performed todetermine a value of a detected physiological property based on ameasurement generated by the second sensor 140 c could be based on adetermined and/or detected alignment of the target 107 c; e.g., anamplitude of a generated measurement could be normalized based on adetected alignment of the target 107 c to correct for effects ofproximity between the target 107 c and the second sensor 140 c onmeasurements generated by the second sensor 140 c.

Additionally or alternatively, a wearable device could include two ormore sensors configured to detect alignment of a target, and one or morefurther sensors configured to detect a physiological or other property(e.g., a blood flow rate, a pulse rate, a blood oxygenation, a bloodtemperature, a concentration of an analyte in blood) of the wearerand/or of the target. The further sensor(s) could be configured todetect the property of the wearer and/or target when the target has aspecified disposition (e.g., location, orientation) relative to thefurther sensor (i.e., when the target is aligned with the furthersensor). The operation of the further sensor to detect the property ofthe wearer and/or target could be performed in response to adetermination (e.g., using the two or more sensors) that the target isaligned with the further sensor. Additionally or alternatively,operation of the further sensor to detect the property of the wearerand/or target could be related to the detected alignment. For example, amapping or other calculation performed to determine a value of adetected property based on a measurement generated by the further sensorcould be based on a determined and/or detected alignment of the target;e.g., an amplitude of a generated measurement could be normalized basedon a detected alignment of the target to correct for effects ofproximity between the target and the further sensor on measurementsgenerated by the further sensor.

FIG. 1D illustrates such a wearable device 100 d. FIG. 1D is a partialcross-sectional view through a human wrist 105 d illustrating an examplewearable device 100 d when mounted to the human wrist 105 d. Thewearable device 100 d could be configured similarly to the wearabledevices 100 a, 100 b, 100 c of FIGS. 1A, 1B, and 1C, and includes ahousing 110 d (e.g., a water-resistant and/or water-proof housing)configured to contain electronic components and to be mounted to anexternal body surface of a wearer by a mount 120 d. The mount 120 d canbe a band configured to enclose the wrist 105 d and to position first140 d and second 140 d sensors in the housing 110 d proximate to atarget 107 d (i.e., a portion of subsurface vasculature) in the wrist105 d. The wearable device 100 d further includes a further sensor 150 dconfigured to detect one or more physiological properties of the wearer(e.g., of the target 107 d) when the target 107 d is aligned with thewearable device 100 d (i.e., aligned with the further sensor 150 d).

As illustrated in FIG. 1D, the target 107 d is located beneath thehousing 110 d, at a location beneath the further sensor 150 d. In someembodiments, the first 130 d and second 140 d sensors could beconfigured to determine the location of the target 107 d relative to thesensors 130 d, 140 d, the housing 110 d, the further sensor 150 d, orsome other element(s) of the wearable device 100 d. That is, detectingalignment of the target 107 d could include operating the sensors 130 d,140 d, to detect the location, orientation, or some other informationabout the disposition of the target 107 d. The further sensor 150 dcould also be configured to detect, alone or in concert with the othersensors 130 d, 140 d, the alignment of the target 107 d. Thus, thesensors 130 d, 140 d could be operated as described above to detect thelocation, orientation, or some other information about the target 107 dand a determination that the target 107 d is aligned could be made basedon such detected information. Additionally or alternatively, the sensors130 d, 140 d could be configured to detect some categorical and/orqualitative information about the alignment of the target 107 d. Forexample, the sensors 130 d, 140 d could be configured to detect that thealignment of the target 107 d corresponds to one of a discrete set ofstates, e.g., ‘aligned,’ ‘nearly aligned,’ ‘not aligned,’ ‘not alignedin a direction toward the first sensor 130 d,’ ‘not aligned in adirection toward the second sensor 140 d,’ etc. In some examples, thesensors 130 d, 140 d could determine that the target 107 d is alignedbased on a property detected by the sensors 130 d, 140 d (e.g., areflected light intensity, an echo signal latency) being substantiallyequal.

Note that the further sensor 150 d could include an energy emitterconfigured to emit some energy (e.g., light, infrared, ultraviolet,acoustic, ultrasonic, electromagnetic, thermal, etc.). The energy couldbe emitted to enable detection of some property of the wearer and/or atarget (e.g., 107 d) by active detection (i.e., illuminating orotherwise exposing the target to energy such that a change in the target(e.g., a fluorescence, a temperature change, a scattering of energy)related to the property can be detected). Alignment of a target with thefurther sensor 150 d could include alignment of the target with theenergy emitter. The further sensor 150 d could include other elements,including but not limited to magnets, filters, polarizers, magneticshimming and/or shielding materials, and diffraction gratings.

Additionally or alternatively, the further sensor 150 d illustrated inFIG. 1D could include some other element, component, or device. In someexamples, the wearable device 100 d could include an energy emitterconfigured to emit some energy (e.g., visible light, infrared light,ultraviolet light, heat, acoustical pulses) in order to effect somechange in the body of the wearer and/or components thereof (e.g., todenature, destroy, or otherwise alter some analyte in the subsurfacevasculature of the wearer that has a negative health effect on thewearer, e.g., a cancer cell). In some examples, the wearable device 100d could include a high-strength magnet configured to attract magneticparticles in a lumen of subsurface vasculature proximate to thehigh-strength magnet, and two or more sensors of the wearable devicecould be configured to detect alignment of the subsurface vasculature(i.e., the target) with the high-strength magnet such that magneticfields emitted by the high-strength magnet can act to attract, collect,or otherwise exert magnetic forces on the magnetic particles. Otherconfigurations, operations, and applications of wearable devices, andalignments with component(s) of such wearable devices to enable orotherwise affect such operations and/or applications, are anticipated.

A wearable device could include a plurality of sensors configured in avariety of ways to enable detection of alignment of a target relative tothe plurality of sensors and/or other component(s) of the wearabledevice. FIG. 1E illustrates such a wearable device 100 e. FIG. 1E is apartial cross-sectional view through a human wrist 105 e illustrating anexample wearable device 100 e when mounted to the human wrist 105 e. Thewearable device 100 e could be configured similarly to the wearabledevices 100 a, 100 b, 100 c of FIGS. 1A, 1B, and 1C, and includes ahousing 110 e (e.g., a water-resistant and/or water-proof housing)configured to contain electronic components and to be mounted to anexternal body surface of a wearer by a mount 120 e. The mount 120 e canbe a band configured to enclose the wrist 105 e and to position aplurality of sensors 131 e, 132 e, 133 e, 134 e, 135 e, 136 e in thehousing 110 e proximate to a target 107 e (i.e., a portion of subsurfacevasculature) in the wrist 105 e.

As illustrated in FIG. 1E, the target 107 e is located beneath thehousing 110 e, at a location proximate to the sensors 131 e, 132 e, 133e, 134 e, 135 e, 136 e. In some embodiments, the sensors 131 e, 132 e,133 e, 134 e, 135 e, 136 e could be configured to determine the locationof the target 107 e relative to the sensors 131 e, 132 e, 133 e, 134 e,135 e, 136 e, the housing 110 e, or some other element(s) of thewearable device 100 e. That is, detecting alignment of the target 107 ecould include operating the sensors 131 e, 132 e, 133 e, 134 e, 135 e,136 e to detect the location, orientation, or some other informationabout the disposition of the target 107 e. In some embodiments, theillustrated location of the target 107 e relative to the sensors 131 e,132 e, 133 e, 134 e, 135 e, 136 e, housing 110 e, and/or othercomponents of the wearable device 100 e could be one of one or morespecified locations, such that the target 107 e is aligned relative toelement(s) of the wearable device 100 e. Thus, the sensors 131 e, 132 e,133 e, 134 e, 135 e, 136 e could be operated as described above todetect the location, orientation, or some other information about thetarget 107 e and a determination that the target 107 e is aligned couldbe made based on such detected information. Additionally oralternatively, the sensors 131 e, 132 e, 133 e, 134 e, 135 e, 136 ecould be configured to detect some categorical and/or qualitativeinformation about the alignment of the target 107 e. For example, thesensors 131 e, 132 e, 133 e, 134 e, 135 e, 136 e could be configured todetect that the alignment of the target 107 e corresponds to one of adiscrete set of states, e.g., ‘aligned,’ ‘nearly aligned,’ ‘notaligned,’ ‘aligned with a first sensor 131 e,’ ‘aligned with a secondsensor 132 e,’ ‘not aligned between a first set of two sensors 131 e,132 e,’ ‘not aligned between a second pair of sensors 132 e, 133 e,’‘not aligned between a third pair of sensors 133 e, 134 e,’ etc. Thatis, in some examples the disposition of the target 107 e relative tocomponent(s) of the wearable device 100 e could be such that the target107 e is not aligned.

FIG. 1F is a partial cross-sectional view through a human wrist 105 fillustrating an example wearable device 100 f when mounted to the humanwrist 105 f. The wearable device 100 f could be configured similarly tothe wearable devices 100 a, 100 b, 100 c, 100 d, 100 e of FIGS. 1A, 1B,1C, 1D, and 1E, and includes a housing 110 f (e.g., a water-resistantand/or water-proof housing) configured to contain electronic componentsand to be mounted to an external body surface of a wearer by a mount 120f. The mount 120 f can be a band configured to enclose the wrist 105 fand to position a plurality of sensors 131 f, 132 f, 133 f, 134 f, 135f, 136 f in the housing 110 f proximate to a target 107 f (i.e., aportion of subsurface vasculature) in the wrist 105 f. The wearabledevice 100 f further includes a further sensor 150 f configured todetect one or more physiological properties of the wearer (e.g., of thetarget 107 f) when the target 107 f is aligned with the wearable device100 f (i.e., aligned with the further sensor 150 f).

As illustrated in FIG. 1F, the target 107 f is located beneath thehousing 110 f, at a location beneath the further sensor 150 d. In someembodiments, the sensors 131 f, 132 f, 133 f, 134 f, 135 f, 136 f couldbe configured to determine the location of the target 107 f relative tothe sensors 131 f, 132 f, 133 f, 134 f, 135 f, 136 f, the housing 110 f,the further sensor 150 f, or some other element(s) of the wearabledevice 100 f. That is, detecting alignment of the target 107 f couldinclude operating the sensors 131 f, 132 f, 133 f, 134 f, 135 f, 136 fto detect the location, orientation, or some other information about thedisposition of the target 107 f. The further sensor 150 f could also beconfigured to detect, alone or in concert with the other sensors 131 f,132 f, 133 f, 134 f, 135 f, 136 f, the alignment of the target 107 f.Thus, the sensors 131 f, 132 f, 133 f, 134 f, 135 f, 136 f could beoperated as described above to detect the location, orientation, or someother information about the target 107 f and a determination that thetarget 107 f is aligned could be made based on such detectedinformation. Additionally or alternatively, the sensors 131 f, 132 f,133 f, 134 f, 135 f, 136 f could be configured to detect somecategorical and/or qualitative information about the alignment of thetarget 107 f. For example, the sensors 131 f, 132 f, 133 f, 134 f, 135f, 136 f could be configured to detect that the alignment of the target107 f corresponds to one of a discrete set of states, e.g., ‘aligned,’‘nearly aligned,’ ‘not aligned,’ ‘aligned with the further sensor 150f,’ ‘aligned with a first sensor 131 f,’ ‘aligned with a second sensor132 f,’ ‘not aligned between a first set of two sensors 131 f, 132 f,’‘not aligned between a second pair of sensors 132 f, 133 f,’ ‘notaligned between a third pair of sensors 134 f, 135 f,’ etc. That is, insome examples the disposition of the target 107 f relative tocomponent(s) of the wearable device 100 f (e.g., the further sensor 150f) could be such that the target 107 f is not aligned.

Note that the further sensor 150 f could include an energy emitterconfigured to emit some energy (e.g., light, infrared, ultraviolet,acoustic, ultrasonic, electromagnetic, thermal, etc.). The energy couldbe emitted to enable detection of some property of the wearer and/or atarget (e.g., 107 f) by active detection (i.e., illuminating orotherwise exposing the target to energy such that a change in the target(e.g., a fluorescence, a temperature change, a scattering of energy)related to the property can be detected). Alignment of a target with thefurther sensor 150 f could include alignment of the target with theenergy emitter. The further sensor 150 f could include other elements,including but not limited to magnets, filters, polarizers, magneticshimming and/or shielding materials, and diffraction gratings.

Additionally or alternatively, the further sensor 150 f illustrated inFIG. 1F could include some other element, component, or device. In someexamples, the wearable device 100 f could include an energy emitterconfigured to emit some energy (e.g., visible light, infrared light,ultraviolet light, heat, acoustical pulses) in order to effect somechange in the body of the wearer and/or components thereof (e.g., todenature, destroy, or otherwise alter some analyte in the subsurfacevasculature of the wearer that has a negative health effect on thewearer, e.g., a cancer cell). In some examples, the wearable device 100f could include a high-strength magnet configured to attract magneticparticles in a lumen of subsurface vasculature proximate to thehigh-strength magnet, and two or more sensors of the wearable devicecould be configured to detect alignment of the subsurface vasculature(i.e., the target) with the high-strength magnet such that magneticfields emitted by the high-strength magnet can act to attract, collect,or otherwise exert magnetic forces on the magnetic particles. Otherconfigurations, operations, and applications of wearable devices, andalignments with component(s) of such wearable devices to enable orotherwise affect such operations and/or applications, are anticipated.

FIG. 1G is a partial cross-sectional view through a human wrist 105 gillustrating an example wearable device 100 g when mounted to the humanwrist 105 g. The wearable device 100 g could be configured similarly tothe wearable devices 100 a, 100 b, 100 c, 100 d, 100 e, 100 f of FIGS.1A, 1B, 1C, 1D, 1E, and 1F and includes a housing 110 g (e.g., awater-resistant and/or water-proof housing) configured to containelectronic components and to be mounted to an external body surface of awearer by a mount 120 g. The mount 120 g can be a band configured toenclose the wrist 105 g and to position a photodetector 130 g and first151 g and second 152 g light emitters in the housing 110 g proximate toa target 107 g (i.e., a portion of subsurface vasculature) in the wrist105 g.

The light emitters 151 g, 152 g could include a varitety oflight-emitting components (e.g., LEDS, lasers, electroluminescent panelsor wire, IR emitters, UV emitters), refracting elements (e.g., lenses,dichroic elements), reflecting elements (e.g., flat or curved mirrors),differacting elements (e.g., gratings), polarizers, half or quarter waveplates, filters, apertures, liquid crystal elements (e.g.,electronically actuated blinds, gratings, and/or apertures) or someother optical and/or light-emitted elements or combination(s) thereof.The light emitters 151 g, 152 g could be configured to emit illuminationhaving one or more specified properties (e.g., a wavelength, a spectralprofile, a degree and/or direction of polarization). Such specifiedproperties of the light emitted by the light emitters 151 g, 152 g couldbe specified such that the light emitted by the light emitters 151 g,152 g is preferentially reflected, refracted, or otherwise scattered bythe target (e.g., by blood in a portion of subsurface vasculature)relative to other elements in the environment of the target (e.g., skin,connective tissue). The light emitters 151 g, 152 g could be configuredto illuminate specified region(s) of the environment of the wearabledevice 100 g (e.g., regions proximate to respective emitters of thelight emitters 151 g, 152 g). Such illuminated regions could be disjointor otherwise distinct or could be wholly or partially overlapping.

The photodetector 130 g could include one or more light sensitiveelements (e.g., light sensors, IR sensors, UV sensors, photodiodes,phototransistors, photoresistors). The photodetector 130 g couldadditionally include one or more light emitters, IR emitters,electromagnetic energy emitters, heaters, vibrators, acoustical energyemitters, force transducers, or some other energy emitters. In additionto detecting alignment of the target 107 g in conjunction with the lightemitters 151 g, 152 g, the photodetector 130 g could be configured todetect one or more properties (e.g., an oxygen saturation, an analytepresense or concentration) of the target 107 g. Such detection could berelated to illumination of the target 107 g by the light emitters 151 g,152 g and/or by emission of energy (e.g., IR, UV, or visible light,heat, electromagnetic radiation, acoustic energy) by an energy emitterof the photodetector 130 g.

Additionally or alternatively, the photodetector 130 g could beconfigured to interact with and/or detect one or more properties ofspecific elements or components of the body of the wearer (e.g., thetarget 107 g). In some examples, the photodetector 130 g and/or lightemitters 152 g, 152 g could act to illuminate or otherwise direct energytoward elements in the body of the wearer (e.g., the target 107 g) andcould detect a light or other energy emitted by, reflected by, scatteredby, or otherwise received from the elements in response to theillumination and/or direction of energy toward the elements. Forexample, one or both of the light emitters 151 g, 152 g and/or a lightemitter of the photodetector 130 g could be configured to illuminate afluorophore, chromophore, or other optic chemical, moiety, analyte, orother element of the body of the wearer and the photodetector 130 gcould detect light emitted, scattered, reflected, or otherwise receivedfrom the element of the body of the wearer in response to theillumination. One or more properties of the illumination and/or of thedetected light could be used to determine one or more properties of thebody of the wearer. For example, an intensity of light received by thephotodetector 130 g when the first light emitter 151 g is emitting lightcould be used to determine whether the target 107 g (a portion ofsubsurface vasculature) is in a specified direction (i.e., a directionof light emitted by the first light emitter 151 g).

As illustrated in FIG. 1G, the target 107 g is located beneath thehousing 110 g, at a location beneath the photodetector 130 g. In someembodiments, the photodetector 130 g and first 151 g and second 152 glight emitters could be configured to determine the location of thetarget 107 g relative to the light emitters 151 g, 151 g, the housing110 g, the photodetector 130 g, or some other element(s) of the wearabledevice 100 g. That is, detecting alignment of the target 107 g couldinclude operating the light emitters 151 g, 152 g and photodetector 130g to detect the location, orientation, or some other information aboutthe disposition of the target 107 g. Thus, the light emitters 151 g, 152g and photodetector 130 g could be operated as described above to detectthe location, orientation, or some other information about the target107 g and a determination that the target 107 g is aligned could be madebased on such detected information. Additionally or alternatively, thelight emitters 151 g, 152 g and photodetector 130 g could be configuredto detect some categorical and/or qualitative information about thealignment of the target 107 g. For example, the light emitters 151 g,152 g and photodetector 130 g could be configured to detect that thealignment of the target 107 g corresponds to one of a discrete set ofstates, e.g., ‘aligned,’ ‘nearly aligned,’ ‘not aligned,’ ‘not alignedin a direction toward the first light emitter 151 g,’ ‘aligned in adirection toward the second light emitter 152 g,’ etc. In some examples,the light emitters 151 g, 152 g and photodetector 130 g could determinethat the target 107 g is aligned based on a property detected by thephotodetector 130 g during periods of operation of the light emitters151 g, 152 g (e.g., a reflected light intensity) being substantiallyequal.

Note that the photodetector 130 g could include an energy emitterconfigured to emit some energy (e.g., light, infrared, ultraviolet,acoustic, ultrasonic, electromagnetic, thermal, etc.). The energy couldbe emitted to enable detection of some property of the wearer and/or atarget (e.g., 107 g) by active detection (i.e., illuminating orotherwise exposing the target to energy such that a change in the target(e.g., a fluorescence, a temperature change, a scattering of energy)related to the property can be detected). Alignment of a target with thephotodetector 130 g could include alignment of the target with theenergy emitter of the photodetector 130 g. The photodetector 130 g couldinclude other elements, including but not limited to magnets, filters,polarizers, magnetic shimming and/or shielding materials, anddiffraction gratings.

Additionally or alternatively, the photodetector 130 g illustrated inFIG. 1F could include some other element, component, or device. In someexamples, the wearable device 100 f could include an energy emitterconfigured to emit some energy (e.g., visible light, infrared light,ultraviolet light, heat, acoustical pulses) in order to effect somechange in the body of the wearer and/or components thereof (e.g., todenature, destroy, or otherwise alter some analyte in the subsurfacevasculature of the wearer that has a negative health effect on thewearer, e.g., a cancer cell). In some examples, the wearable device 100f could include a high-strength magnet configured to attract magneticparticles in a lumen of subsurface vasculature proximate to thehigh-strength magnet, and the photodetector 130 g and light emitters 151g, 152 g or some other sensor(s) of the wearable device 100 g could beconfigured to detect alignment of the subsurface vasculature (i.e., thetarget) with the high-strength magnet such that magnetic fields emittedby the high-strength magnet can act to attract, collect, or otherwiseexert magnetic forces on the magnetic particles. Other configurations,operations, and applications of wearable devices, and alignments withcomponent(s) of such wearable devices to enable or otherwise affect suchoperations and/or applications, are anticipated.

A wearable device could include a plurality of light emitters and/orsensors configured in a variety of ways to enable detection of alignmentof a target relative to the plurality of light emitters, sensors, and/orother component(s) of the wearable device. FIG. 1H illustrates such awearable device 100 h. FIG. 1H is a partial cross-sectional view througha human wrist 105 h illustrating an example wearable device 100 h whenmounted to the human wrist 105 h. The wearable device 100 h could beconfigured similarly to the wearable devices 100 a, 100 b, 100 c, 100 d,100 e, 100 f, 100 g of FIGS. 1A, 1B, 1C, 1D, 1E, 1F, and 1G, andincludes a housing 110 h (e.g., a water-resistant and/or water-proofhousing) configured to contain electronic components and to be mountedto an external body surface of a wearer by a mount 120 h. The mount 120h can be a band configured to enclose the wrist 105 h and to position aplurality of sensors 130 h, 140 h, 145 h and light emitters 151 h, 152h, 153 h, 154 h, 155 h, 156 h in the housing 110 h proximate to a target107 h (i.e., a portion of subsurface vasculature) in the wrist 105 h.

As illustrated in FIG. 1H, the target 107 h is located beneath thehousing 110 e, at a location proximate to the sensors 130 h, 140 h, 145h and light emitters 151 h, 152 h, 153 h, 154 h, 155 h, 156 h. In someembodiments, the sensors 130 h, 140 h, 145 h and light emitters 151 h,152 h, 153 h, 154 h, 155 h, 156 h could be configured to determine thelocation of the target 107 h relative to the sensors 130 h, 140 h, 145 hand light emitters 151 h, 152 h, 153 h, 154 h, 155 h, 156 h, the housing110 h, or some other element(s) of the wearable device 100 h. That is,detecting alignment of the target 107 h could include operating thesensors 130 h, 140 h, 145 h and light emitters 151 h, 152 h, 153 h, 154h, 155 h, 156 h to detect the location, orientation, or some otherinformation about the disposition of the target 107 h. In someembodiments, the illustrated location of the target 107 h relative tothe sensors 130 h, 140 h, 145 h and light emitters 151 h, 152 h, 153 h,154 h, 155 h, 156 h, housing 110 h, and/or other components of thewearable device 100 h could be one of one or more specified locations,such that the target 107 h is aligned relative to element(s) of thewearable device 100 h. Thus, the sensors 130 h, 140 h, 145 h and lightemitters 151 h, 152 h, 153 h, 154 h, 155 h, 156 h could be operated asdescribed above to detect the location, orientation, or some otherinformation about the target 107 h and a determination that the target107 h is aligned could be made based on such detected information.Additionally or alternatively, the sensors 130 h, 140 h, 145 h and lightemitters 151 h, 152 h, 153 h, 154 h, 155 h, 156 h could be configured todetect some categorical and/or qualitative information about thealignment of the target 107 h. For example, the sensors 130 h, 140 h,145 h and light emitters 151 h, 152 h, 153 h, 154 h, 155 h, 156 h couldbe configured to detect that the alignment of the target 107 hcorresponds to one of a discrete set of states, e.g., ‘aligned,’ ‘nearlyaligned,’ ‘not aligned,’ ‘aligned with a first sensor 130 h,’ ‘alignedwith a second sensor 140 h,’ ‘aligned with a second light emitter 152h,’ ‘aligned with a fourth light emitter 154 h,’ ‘not aligned between afirst set of two sensors 130 h, 140 h,’ ‘not aligned between a firstpair of light emitters 152 h, 153 h,’ ‘not aligned between a second pairof light emitters 153 h, 154 h,’ etc. That is, in some examples thedisposition of the target 107 h relative to component(s) of the wearabledevice 100 h could be such that the target 107 h is not aligned.

Note that the sets of sensors 130 g, 130 h, 140 h, 145 h and lightemitters 151 g, 512 g, 151 h, 152 h, 153 h, 154 h, 155 h, 156 h of theillustrated wearable devices 100 g, 100 h are disposed as linear arrays.This could be advantageous in certain applications. For example,applications wherein alignment of a wearable device and/or componentsthereof is more sensitive to motion of the wearable device in onedirection relative to the target than in a perpendicular direction(e.g., when the target is a long object, e.g., a portion of subsurfacevasculature). Other applications wherein a linear arrays of sensorsand/or light emitters could be advantageous include applications whereinadjustment of and/or motion between the target and the wearable deviceis largely constrained to a single direction/degree of freedom (e.g.,when the wearable device is mounted to a protruding element of awearer's anatomy (e.g., a wrist, and ankle, a limb)). However, manyapplications are anticipated wherein an array of two or more alignment-or other property-sensing sensors and/or light emitters are arranged in2-dimensional patterns (e.g., rectangular, hexagonal, triangular, orother regularly or irregularly spaced grids, tessellations, or otherpatterns). Such 2-dimensional arrays of sensors could be furtherconfigured and/or operated to detect information about a target and/orabout a wearer in addition to information about alignment of the target.For example, a 2-dimensional array of sensors and/or light emitterscould be operated to detect a pattern, size, or other information aboutsubsurface vasculature, nerves, or other anatomical or physiologicalelements of a wearer.

Further, individual sensors and/or light emitters in an array of sensorsand/or light emitters could be discrete sensors (e.g., sensors composedof individual discrete photodetectors, photodiodes, LEDs, thermistors,micro-cameras, or other discrete components and/or sensors) or lightemitters (e.g., light emitters composed of individual discrete LEDS,semiconductor lasers, VCSELs) or could be part of a single chip,multi-chip module, lithographed element, or other composite element ordevice. Further, an array of sensors and/or light emitters could includea combination of discrete sensor and/or light emitter components andmulti-sensor and/or multi-light-emitter integrated components. Forexample, an array of sensors and/or light emitters could include asingle-chip array of VCSELs, a linear or planar CCD array, an array ofPZT or other acoustic and/or piezoelectric transducers, or some otherelement that includes multiple sensors and/or light emitters. Thesensors and/or light emitters in an array of sensors and/or lightemitters could be substantially identical, or could include two or moretypes of sensors and/or light emitters. Some or all of the sensorsand/or light emitters in an array of sensors and/or light emitters couldbe configured and/or operated to detect alignment of a target; further,some or all of the sensors and/or light emitters could be configuredand/or operated to detect other information about a wearer and/or atarget on or within the wearer.

A wearable device (e.g., 100 a, 100 b, 100 c, 100 d, 100 e, 100 f, 100g, 100 h) could be operated based on a detected alignment of a target(e.g., a portion of subsurface vasculature). For example, one or moresensors and/or light emitters of the wearable device could be operatedto detect a property of the target when the alignment of the target isdetected. The one or more sensors could be sensors additionally used todetect the alignment of the target or could be different sensors. Insome examples, the sensors and/or light emitters could be operated‘opportunistically,’ i.e., operated during time periods during whichmovements of the target, the wearer, the wearable device, and/orcomponents of the wearable device result in alignment of the targetand/or other elements of interest on or within the body of the wearerwith one or more sensors or other elements of the wearable device. Insome examples, accelerometers, optic flow sensors, or other devices ofthe wearable device could be operated to allow the location and/or otherinformation about the disposition of the target to be predicted based ona detected alignment of the target detected during a previous timeperiod. This predicted location and/or other information could be usedto predict that the target is aligned or about to be aligned and tooperate the wearable device (e.g., to detect a property of the target)based on the predicted alignment. This could be particularlyadvantageous in applications where a sensor has a high energyrequirement and/or requires a period of time to become active and/or tomake a measurement. That is, such a sensor could be maintained in adisabled and/or low-power state until the wearable device predicts thatthe target will be and/or is currently aligned (based on a predictedfuture/current alignment and/or a detected alignment using sensorsand/or light emitters of the wearable device); the sensor could then beactivated and/or operated to make a measurement.

Additionally or alternatively, a wearable device could be configuredand/or operated to align one or more components and/or to indicate analignment to a user such that the target is aligned with one or morecomponents of the wearable device. This could include the wearabledevice including servos or other actuators configured to control alocation of one or more components of the wearable device relative tothe target (e.g., the example wearable device 200 illustrated in FIGS.2A and 2B). Additionally or alternatively, this could include thewearable device indicating to a wearer an adjustment of the location ofthe wearable device and/or of some subcomponent of the wearable deviceto align one or more components of the wearable device relative to thetarget (e.g., the example wearable device 300 illustrated in FIGS. 3A,3B, 3C, and 3D).

FIGS. 2A and 2B are partial cross-sectional views through a human wrist205 illustrating an example wearable device 200 when mounted to thehuman wrist 205. The wearable device 200 includes a housing 210 (e.g., awater-resistant and/or water-proof housing) configured to containelectronic components and to be mounted to an external body surface of awearer by a mount 220. The mount 220 can be a band configured to enclosethe wrist 205 and to position first 230 and second 240 sensors in thehousing 210 proximate to a target 207 (i.e., a portion of subsurfacevasculature) in the wrist 205. The first 230 and second 240 sensors aredisposed in a sensor carriage 260 that is disposed within the housing210 and that can be moved (e.g., by a servo, piezoelectric element,solenoid, or some other electrical and/or mechanical actuator) tocontrol the location of the first 230 and second 240 sensors. Thewearable device 200 includes additional elements that are not shown,e.g., electronics configured to operate the first 230 and second 240sensors, to operate actuators to control to location of the sensorcarriage 260, and to enable applications and/or functions of thewearable device 200, a rechargeable battery configured to power thewearable device 200, or other components. Components of the wearabledevice 200 could be disposed on or within the housing 210, the mount220, or some other elements of the wearable device 200 (not shown);e.g., a second housing.

As illustrated in FIG. 2A, the target 207 is located beneath the housing210, at a location between the first 230 and second 240 sensors. In someembodiments, the first 230 and second 230 sensors could be configured todetermine the location of the target 207 relative to the sensors 230,240, the sensor carriage 260, the housing 210, or some other element(s)of the wearable device 200. That is, detecting alignment of the target207 could include operating the sensors 230, 240, to detect thelocation, orientation, or some other information about the dispositionof the target 207. As illustrated in FIG. 2B, the location of the sensorcarriage 260 has been controlled (e.g., by the wearable device operatinga servo, motor, piezoelectric element, or other actuator) such that thesensor 230, 240 are aligned (i.e., equidistant from) the target 207.

Controlling the location of the sensor carriage 260 (and thus of thesensors 230, 240) could be performed continuously, at one or morespecified periods of time, or according to some other consideration orcombination of considerations. For example, a measurement of a propertyof the target 207 and/or of the wearer could be contingent uponalignment of the sensor 230, 240 with the target 207 and could beperformed at one or more specified points in time. The sensor carriage260 could be located to align with the target 207 during the one or morespecified points in time and allowed to become un-aligned (e.g., bycontrolled or uncontrolled motions of the target 207, the wearer, thewearable device 200, the sensor carriage 260, or some other element orelements) at times other than the one or more specified points in time.Additionally or alternatively, the sensors 230, 240 could becontinuously and/or periodically operated to detect the alignment of thetarget 207 and the location of the sensor carriage 260 could beresponsively operated. In some examples, this could include continuouslycontrolling the location of the sensor carriage 260 to align the target207 with the sensors 230, 240 and/or other components of the wearabledevice 200. In some examples, this could include controlling thelocation of the sensor carriage 260 to align the target 207 with thesensors 230, 240 and/or other components of the wearable device 200 whenthe detected alignment has decreased below some threshold (e.g., thedetected alignment is more that 5 mm away from a specified alignment).Other operations of the wearable devices as describe herein will beevident to one of skill in the art are anticipated. Further, alignmentof the target 207 could include aligning the target 207 with differentelements of the wearable device 200 at different points in time, and thecontrolled location of the sensor carriage 260 at different points intime could reflect this. Note that the sensor carriage 260 couldalternatively include two or more light emitters and one or morephotodetectors configured to determine the location of the target 207relative to the two or more light emitters, the one or morephotodetectors, the sensor carriage 260, the housing 210, or some otherelement(s) of the wearable device 200.

A wearer or other user of a wearable device (e.g., 100 a, 100 b, 100 c,100 d, 100 e, 100 f, 100 g, 100 h, 200) could operate, dispose, adjust,or otherwise locate the wearable device and/or components thereof toalign one or more components (e.g., a sensor, a light emitter) of thewearable device with a target or other component on or within the bodyof the wearer. The wearable device could operate two or more sensors(e.g., photodetectors, thermistors, or some other sensors) and/or two ormore light emitters and one or more photodetectors to detect alignmentof the target and could indicate (e.g., by a display, an emitted sound,a vibration, or some other indicating means) the detected alignment tothe wearer or to some other user such that the wearer or other usercould adjust the location of the one or more components of the wearabledevice with the target.

FIGS. 3A and 3C are partial cross-sectional views through a human wrist305 illustrating an example wearable device 300 when mounted to thehuman wrist 305. The wearable device 300 includes a housing 310 (e.g., awater-resistant and/or water-proof housing) configured to containelectronic components and to be mounted to an external body surface of awearer by a mount 320. The mount 320 can be a band configured to enclosethe wrist 305 and to position first 330 and second 340 sensors in thehousing 210 proximate to a target 307 (i.e., a portion of subsurfacevasculature) in the wrist 305. The wearable device 300 additionallyincludes a display 360 (illustrated in top views in FIG. 3B and 3D)configured to present information to a user and/or to receive inputs orcommands from the user. The wearable device 300 includes additionalelements that are not shown, e.g., electronics configured to operate thefirst 330 and second 340 sensors, to operate the display 350, and toenable applications and/or functions of the wearable device 300, arechargeable battery configured to power the wearable device 300, orother components. Components of the wearable device 300 could bedisposed on or within the housing 310, the mount 320, or some otherelements of the wearable device 300 (not shown); e.g., a second housing.

As illustrated in FIG. 3A, the target 307 is located beneath the housing310, at a location between the first 330 and second 340 sensors. In someembodiments, the first 330 and second 330 sensors could be configured todetermine the location of the target 307 relative to the sensors 330,340, the housing 310, or some other element(s) of the wearable device300. That is, detecting alignment of the target 307 could includeoperating the sensors 330, 340, to detect the location, orientation, orsome other information about the disposition of the target 307.Correspondingly, the display 360 (as shown in FIG. 3B) could be operatedto present a relative alignment display 370 a indicating that the target307 is not aligned, and that the wearer could adjust the wearable device300 in the indicated direction in order to align the wearable device 300with the target 307. Additionally or alternatively, the display 360could be operated to present an absolute alignment display 380 aincluding an alignment indicator 384a having a distance and directionfrom an alignment mark 382 a indicating a degree and direction to whichthe target 307 is not aligned, and that the wearer could adjust thewearable device 300 in the indicated direction by the indicated amountin order to align the wearable device 300 with the target 307.

As illustrated in FIG. 3C, the target 307 is located beneath the housing310, at a location midway between the first 330 and second 340 sensorssuch that the target 307 is aligned with the wearable device 300.Correspondingly, the display 360 (as shown in FIG. 3D) could be operatedto present a relative alignment display 370 a indicating that the target307 is aligned. Additionally or alternatively, the display 360 could beoperated to present an absolute alignment display 380 b including analignment indicator 384 b whose substantially overlap with an alignmentmark 382 b indicates that the target 307 is aligned.

Indicating alignment (e.g., presenting the relative 370 a/b and/orabsolute 380 a/b alignment display and/or using some other method ofindication) could be performed continuously, at one or more specifiedperiods of time, or according to some other consideration or combinationof considerations. For example, a measurement of a property of thetarget 307 and/or of the wearer could be contingent upon alignment ofthe sensors 330, 340 with the target 307 and could be performed at oneor more specified points in time. The display 360 or other components ofthe wearable device 300 could be operated to indicate the alignmentand/or to instruct the wearer to perform an adjustment of the locationof the wearable device 300 during the one or more specified points intime and allowed to become un-aligned (e.g., by controlled oruncontrolled motions of the target 307, the wearer, the wearable device300, or some other element or elements) at times other than the one ormore specified points in time. Additionally or alternatively, thesensors 330, 340 could be continuously and/or periodically operated todetect the alignment of the target 307 and the display 360 could beresponsively operated to indicate an adjustment and/or alignment. Insome examples, this could include continuously presenting the relative370 a/b and/or absolute 380 a/b alignment display and/or indicating anadjustment or alignment by some other means. In some examples, thiscould include presenting the relative 370 a/b and/or absolute 380 a/balignment display and/or indicating an adjustment or alignment by someother means when the detected alignment has decreased below somethreshold (e.g., the detected alignment is more that 5 mm away from aspecified alignment). Other operations of the wearable devices asdescribe herein will be evident to one of skill in the art areanticipated. Further, alignment of the target 307 could include aligningthe target 307 with different elements of the wearable device 300 atdifferent points in time, and the indication of alignment (using, e.g.,the display 360) could reflect this.

Note that the indications shown in FIGS. 3B and 3D are exemplary, andnot intended to be limiting. A wearable device could present differentor additional indications on a display related to the alignment of atarget. A display of a wearable device could additionally be operated topresent additional or alternate information to a wearer. Further, adisplay of a wearable device could have a different shape or includeadditional or alternative elements. For example, an array of LEDs orother light emitters could be included in a wearable device and could beoperated to indicate information about alignment of a target relative toone or more components of the wearable device such that a wearer couldadjust the wearable device to align the target. Alternate methods couldbe employed to indicate alignment information to a wearer, includingvibration (e.g., using a vibrator motor in the wearable device), sound(e.g., using speakers and/or piezo elements of the wearable device), orsome other method. In some examples, the wearable device could include awireless transceiver or some other means of communication configured totransmit alignment information to another device (e.g., a smartphone, arobotic actuator) and the other device could indicate the alignmentinformation (e.g., using a display of the other device) and/or adjustthe location of components of the wearable device (e.g., by manipulatingthe wearable device and/or components thereof using a robotic actuator).

Note that FIGS. 3A and 3C illustrate adjustment of the wearable device300 taking the form of rotation of the entire wearable device 300 aboutthe wrist 305. This is a non-limiting example of an adjustment of awearable device and/or components thereof that could be effected by awearer or other user in response to indication of an adjustment and/oralignment. In some examples, adjustment by the wearer could includerepositioning a wearable device in some other way (e.g., by moving thedevice up or down the limb of the wearer). In some examples, adjustmentby the wearer could include manipulating and/or reconfiguring somemechanism(s) of the wearable device to align one or more components ofthe wearable device with the target according to some indication of thewearable device. In some examples, the wearable device could indicateother adjustments and/or reconfigurations to be performed by the wearer(e.g., application and/or rotation of a filter, reconfiguring thewearable device into a different mechanical or other configurationrelated to a different operational mode of the wearable device).

Note that the wearable device 300 could additionally or alternativelyinclude two or more light emitters and one or more photodetectorsconfigured to determine the location of the target 307 relative to thetwo or more light emitters, the one or more photodetectors, the housing310, or some other element(s) of the wearable device 300.

Note that the alignment of the targets (e.g., 207, 307), as well as thecontrol and/or adjustment of the location of one or more sensors orother components (e.g., 230, 240, 331, 332, 333, 334, 335, 336, 350), asillustrated in FIGS. 2A, 2B, 3A and 3C, is one-dimensional. That is, thelocation of the sensors and other components of the illustrated examplewearable device (e.g., 200, 300) is only illustrated as being controlledin one direction. It is anticipated that control of the location ofsensors, light emitters, or other components of a wearable device toalign such sensors or other components could be controlled in two ormore dimensions, according to an application. In some examples, thiscould include a wearable device being configured to control the locationof sensors, light emitters, or other components (e.g., using servos orother actuators) in two or more dimensions. In some examples, this couldinclude a wearable device indicating to a wearer or other user to adjustthe location of the wearable device and/or one or more componentsthereof in two or more dimensions (e.g., the wearable device could bemounted around a wrist of the wearer, and the wearable device couldindicate a rotation of the wearable device about the wrist and adisplacement of the wearable device toward or away from the end of thelimb). In some examples, a wearable device could be configured tocontrol the location of (e.g., by operating a servo or other actuator)one or more components of the wearable device (e.g., a sensor, a lightemitter) and to indicate to a wearer or other user some adjustment ofthe wearable device or components thereof to effect alignment of atarget with the wearable device.

Note that example devices herein are configured to be mounted to and toalign with targets within a wrist of a wearer. However, the embodimentsdescribed herein could be applied to other body parts (e.g., an ankle, athigh, a chest, a forehead, a thigh, a finger), or to detect alignmentof targets in other environments. For example, embodiments describedherein could be applied to detect the alignment of a target (e.g., afluid conduit, a tube, a sample container, an analyte-attracting and/orconcentrating device) in an environment (e.g., a natural environment, anenvironment of an industrial, pharmaceutical, or water treatmentprocess) relative to some apparatus using two or more sensors of theapparatus.

Sensors and/or detectors as described herein could include a widevariety of components configured to detect properties of a wide varietyof physical parameters. Sensors and/or detectors could includephotodetectors, temperature sensors, visible light sensors, infraredsensors, ultraviolet sensors, cameras, force transducers, acousticaltransducers, piezo elements, electromagnetic field sensors, radiationsensors, electrical current and/or voltage sensors, magnetic fieldsensors, electric field sensors, or any other sensors or combinations ofsensors that could be configured to detect some information about thealignment of a target relative to the sensors and/or to one or morecomponents of a device comprising the sensors. Photodetectors could beconfigured to detect one or more properties of light received from atarget and/or an environment containing the target and could includephotodiodes, phototransistors, active pixel sensors, CCD sensors, orsome other light-sensitive elements. Photodetectors could be configuredto detect a color, an intensity, a wavelength, a spectrum, apolarization, or some other property or properties of received light.

Sensors and/or detectors as described herein could additionally includeand/or be configured to operate in concert with energy emitters. Energyemitters could include light emitters, infrared emitters, ultravioletemitters, acoustical and/or ultrasonic emitters, electromagnetic fieldemitters, microwave emitters, heaters, or some other componentsconfigured to emit and/or direct energy toward a target and/or anenvironment containing a target. Light emitters could include LEDs,lasers, VCSELs, or other elements and could be configured to emit lighthaving one or more specified properties. For example, the target couldbe subsurface vasculature beneath skin of a wearer, and the emittedlight could have a specified wavelength (e.g., 400 nanometers) such thatthe emitted light minimally interacts with tissue of the wearer otherthan blood in the subsurface vasculature.

The sensors and/or detectors could be operated to detect one or more ofa variety of properties of a wearer of the wearable device via anexternal body surface of the wearer e.g., by contacting, directingenergy (e.g., electrical, magnetic, illumination, acoustic waves)through/into, detecting energy (e.g., electrical, magnetic,illumination, acoustic waves) received from/through, or otherwiseinteracting with and/or through an external body surface of the wearer(i.e., skin of the wearer's wrist). For example, light could be emittedtoward an external body surface of a wearer to illuminate the externalbody surface, and one or more properties of light received from theexternal body surface could be detected (e.g., using the photodiode).This illumination and detection could be used to detect an oxygenationstate of blood proximate to the wearable device (e.g., in a portion ofsubsurface vasculature), a heart rate of the wearer, a flow profile ofthe blood in vasculature of the wearer, or some other information. Thesensors could be configured to detect one or more properties of acontrast agent (e.g., a functionalized fluorophore, chromophore,magnetic particle, or some other natural or artificial contrast agent)in the body of the wearer according to an application.

In some examples, sensors of a device could be configured to detectalignment of a target by detecting the location, orientation, alignment,and/or other information about the disposition of an alignment feature.An alignment feature could be any element(s) within or on the surface ofthe body of a wearer that has a predictable and/or stable spatialrelationship with a target. For example, an alignment feature could be atendon, nerve, or other anatomical feature that is proximate to aportion of subsurface vasculature (i.e., a target). The alignmentfeature could have a known and/or specified spatial relationship withthe target and/or the spatial relationship between the alignment featureand the target could be determined by a wearable device using sensors ofthe wearable device. Note that references herein to a wearable or otherdevice detecting alignment of a target could equally apply to thewearable or other device detecting the location, orientation, alignmentand/or other information about the disposition of an alignment feature.

The alignment feature could be artificial. The alignment feature couldbe a pigment applied to the surface and/or within the skin of a wearer.For example, the alignment feature could be a tattoo. The alignmentfeature could be an implanted device or object(s). One or moreproperties of the alignment feature could enable detection of thelocation, orientation, alignment, or other disposition information aboutthe alignment feature. For example, the alignment feature could includefluorescent pigments or coatings and/or pigments or surface treatmentshaving a specified color. The alignment feature could have a specifiedshape or geometry to enable detection of the alignment feature and/ordetect a location on or within the alignment feature. For example, thealignment feature could be a tattoo applied around the wrist of a wearerand including a series of gray-coded or otherwise spatially-encoded barsor other features such that a device mounted to the wrist coulddetermine the alignment of the device relative to elements of the wrist(e.g., bones, blood vessels, tendons, nerves) based on the patterns ofthe tattoo detected by the device. The alignment feature could beapplied and/or inserted in the body of a wearer such that is has aspecified spatial relationship with a target and/or the spatialrelationship between a target and the alignment feature could bedetermined after application and/or insertion. Other embodiments and/orapplications of natural (e.g., anatomical) and artificial alignmentfeatures are anticipated.

Wearable devices and other embodiments as described herein can include avariety of components configured in a variety of ways. Devices describedherein could include electronics including a variety of differentcomponents configured in a variety of ways to enable applications of thewearable device. The electronics could include controllers, amplifiers,switches, display drivers, touch sensors, wireless communicationschipsets (e.g., Bluetooth radios or other radio transceivers andassociated baseband circuitry to enable wireless communications betweenthe wearable device and some other system(s)), or other components. Theelectronics could include a controller configured to operate one or moresensors and/or components of sensors to detect alignment of a targetand/or one or more properties of the body of the wearer. The controllercould include a processor configured to execute computer-readableinstructions (e.g., program instructions stored in data storage of thewearable device) to enable applications of the wearable device. Theelectronics can include additional or alternative components accordingto an application of the wearable device.

Wearable devices as described herein could include one or more userinterfaces. A user interface could include a display configured topresent an image to a wearer and to detect one or more finger presses ofa wearer on the interface. The controller or some other component(s) ofthe electronics could operate the user interface to provide informationto a wearer or other user of the device and to enable the wearer orother user to affect the operation of the wearable device, to determinesome property of the wearable device and/or of the wearer of thewearable device (e.g., an alignment of a target relative to one or morecomponents of the wearable device), or to provide some otherfunctionality or application to the wearer and/or user. As one example,the user interface could be operated to indicate information about thealignment of a target to the wearer. As another example, the wearercould press an indicated region of the user interface to indicate thatthe wearable device should begin logging detected medical informationabout the wearer. Other indicated information, changes in operation ofthe wearable device, or other functions and applications of the userinterface are anticipated.

Note that the embodiments illustrated in FIGS. 1A-H, 2A-B, and 3A-D areillustrative examples and not meant to be limiting. Alternativeembodiments, including more or fewer components in alternativeconfigurations are anticipated. A wearable device could include multiplehousings or other such assemblies each containing some set of componentsto enable applications of such a wearable device. For example, awearable device could include a first housing within which are disposedsensors and/or light emitters configured to detect the alignment of atarget relative to the first housing/sensors and/or light emitters and asecond housing containing a user interface and electronics configured tooperate the sensors and/or light emitters and to present information toand receive commands from a user of the wearable device. A wearabledevice could be configured to perform a variety of functions and toenable a variety of applications. Wearable devices could be configuredto operate in concert with other devices or systems; for example,wearable devices could include a wireless communication interfaceconfigured to transmit data indicative of one or more properties of thebody of a wearer of the wearable device. Other embodiments, operations,configurations, and applications of a wearable device as describedherein are anticipated.

A wearable device 400 (illustrated in FIG. 4) can automatically detectalignment of a target relative to the wearable device 400 and/or measurea plurality of physiological parameters of a person wearing the device.The term “wearable device,” as used in this disclosure, refers to anydevice that is capable of being worn at, on or in proximity to a bodysurface, such as a wrist, ankle, waist, chest, or other body part. Inorder to take in vivo measurements in a non-invasive manner from outsideof the body, the wearable device may be positioned on a portion of thebody where subsurface vasculature or other targets or elements of thebody of the wearer are easily observable, the qualification of whichwill depend on the type of detection system used. The device may beplaced in close proximity to the skin or tissue. A mount 410, such as abelt, wristband, ankle band, etc. can be provided to mount the deviceat, on or in proximity to the body surface. The mount 410 may preventthe wearable device from moving relative to the body to reducemeasurement error and noise. In one example, shown in FIG. 4, the mount410, may take the form of a strap or band 420 that can be worn around apart of the body. Further, the mount 410 may be an adhesive substratefor adhering the wearable device 400 to the body of a wearer.

A housing 430 is disposed on the mount 410 such that it can bepositioned on the body. A contact surface 440 of the housing 430 isintended to be mounted facing to the external body surface. The housing430 may include sensors 451, 452, 453, 454, 455, 456 for detecting thealignment of a target (e.g., a portion of subsurface vasculature)relative to the sensors 451, 452, 453, 454, 455, 456 and/or some otherelement(s) of the wearable device 400. The housing 430 may furtherinclude at least one further sensor 460 for detecting at least oneproperty of the target and/or some other element on or within the bodyof the wearer, which could include any parameters that may relate to thehealth of the person wearing the wearable device. For example, thefurther sensor 480 could be configured to measure blood pressure, pulserate, respiration rate, skin temperature, etc. In a non-exhaustive list,the sensors 451, 452, 453, 454, 455, 456 and further sensor 480 mayinclude any one or more of an optical (e.g., CMOS, CCD, photodiode),acoustic (e.g., piezoelectric, piezoceramic), electrochemical (voltage,impedance), thermal, mechanical (e.g., pressure, strain), magnetic, orelectromagnetic (e.g., magnetic resonance) sensor. Components disposedin the housing 430 may be miniaturized so that the wearable device maybe worn on the body without significantly interfering with the wearer'susual activities. The wearable device additionally includes electronicsconfigured to enable functions of the wearable device 400 includingoperating the sensors 451, 452, 453, 454, 455, 456 to detect alignmentwith a target on or within the body of a wearer. Alternatively, theillustrated 451, 452, 453, 454, 455, 456 could be light emitters and theillustrated 460 could be a photodetector configured detect the alignmentof the target relative to the light emitters 451, 452, 453, 454, 455,456, photodetector 460, and/or other elements of the wearable device400.

The wearable device 400 may also include a user interface 490 via whichthe wearer of the device may receive one or more recommendations oralerts generated either from a remote server or other remote computingdevice, or from a processor within the device. The alerts could be anyindication that can be noticed by the person wearing the wearabledevice. For example, the alert could include a visual component (e.g.,textual or graphical information on a display), an auditory component(e.g., an alarm sound), and/or tactile component (e.g., a vibration).Further, the user interface 490 may include a display 492 where a visualindication of the alert or recommendation may be displayed. The display492 may further be configured to provide an indication of the measuredalignment and/or to indicate an adjustment which could be made by thewearer to align a target with the wearable device.

In some examples, the wearable device is provided as a wrist-mounteddevice, as shown in FIGS. 5A and 5B. The wrist-mounted device may bemounted to the wrist of a living subject with a wristband or cuff,similar to a watch or bracelet. As shown in FIGS. 5A and 5B, the wristmounted device 500 may include a mount 510 in the form of a wristband520, a housing 530 containing a data collection system and positioned onthe anterior side 540 of the wearer's wrist, and a user interface 550positioned on the posterior side 560 of the wearer's wrist. The wearerof the device may receive, via the user interface 550, one or morerecommendations or alerts generated either from a remote server or otherremote computing device, or alerts from the measurement platform. Such aconfiguration may be perceived as natural for the wearer of the devicein that it is common for the posterior side 560 of the wrist to beobserved, such as the act of checking a wrist-watch. Accordingly, thewearer may easily view a display 570 on the user interface. Further, thehousing 530 may be located on the anterior side 540 of the wearer'swrist where the subsurface vasculature or other elements of the body ofthe wearer may be readily observable. However, other configurations arecontemplated.

The display 570 may be configured to display a visual indication of thealert or recommendation and/or an indication of the measured alignmentof a target relative to the wearable device 500. Further, the userinterface 550 may include one or more buttons 580 for accepting inputsfrom the wearer. For example, the buttons 580 may be configured tochange the text or other information visible on the display 570. Asshown in FIG. 5B, housing 530 may also include one or more buttons 590for accepting inputs from the wearer. The buttons 590 may be configuredto accept inputs for controlling aspects of the data collection system,such as initiating a measurement period, or inputs indicating thewearer's current health state (i.e., normal, migraine, shortness ofbreath, heart attack, fever, “flu-like” symptoms, food poisoning, etc.).

FIG. 6 is a simplified schematic of a system including one or morewearable devices 600. The one or more wearable devices 600 may beconfigured to transmit data via a communication interface 610 over oneor more communication networks 620 to a remote server 630. In oneembodiment, the communication interface 610 includes a wirelesstransceiver for sending and receiving communications to and from theserver 630. In further embodiments, the communication interface 610 mayinclude any means for the transfer of data, including both wired andwireless communications. For example, the communication interface mayinclude a universal serial bus (USB) interface or a secure digital (SD)card interface. Communication networks 620 may be any one of may be oneof: a plain old telephone service (POTS) network, a cellular network, afiber network and a data network. The server 630 may include any type ofremote computing device or remote cloud computing network. Further,communication network 620 may include one or more intermediaries,including, for example wherein the wearable device 600 transmits data toa mobile phone or other personal computing device, which in turntransmits the data to the server 630.

In addition to receiving communications from the wearable device 600,such as collected physiological parameter data and data regarding healthstate as input by the user and/or one or more properties of a wearerdetected using a sensor disposed in the wearable device 600, the servermay also be configured to gather and/or receive either from the wearabledevice 600 or from some other source, information regarding a wearer'soverall medical history, environmental factors and geographical data.For example, a user account may be established on the server for everywearer that contains the wearer's medical history. Moreover, in someexamples, the server 630 may be configured to regularly receiveinformation from sources of environmental data, such as viral illness orfood poisoning outbreak data from the Centers for Disease Control (CDC)and weather, pollution and allergen data from the National WeatherService. Further, the server may be configured to receive data regardinga wearer's health state from a hospital or physician. Such informationmay be used in the server's decision-making process, such as recognizingcorrelations and in generating clinical protocols.

Additionally, the server may be configured to gather and/or receive thedate, time of day and geographical location of each wearer of the deviceduring each measurement period. Such information may be used to detectand monitor spatial and temporal spreading of diseases. As such, thewearable device may be configured to determine and/or provide anindication of its own location. For example, a wearable device mayinclude a GPS system so that it can include GPS location information(e.g., GPS coordinates) in a communication to the server. As anotherexample, a wearable device may use a technique that involvestriangulation (e.g., between base stations in a cellular network) todetermine its location. Other location-determination techniques are alsopossible.

The server may also be configured to make determinations regarding theefficacy of a drug or other treatment based on information regarding thedrugs or other treatments received by a wearer of the device and, atleast in part, the physiological parameter data and the indicated healthstate of the user. From this information, the server may be configuredto derive an indication of the effectiveness of the drug or treatment.For example, if a drug is intended to treat nausea and the wearer of thedevice does not indicate that he or she is experiencing nausea afterbeginning a course of treatment with the drug, the server may beconfigured to derive an indication that the drug is effective for thatwearer. In another example, a wearable device may be configured tomeasure blood glucose. If a wearer is prescribed a drug intended totreat diabetes, but the server receives data from the wearable deviceindicating that the wearer's blood glucose has been increasing over acertain number of measurement periods, the server may be configured toderive an indication that the drug is not effective for its intendedpurpose for this wearer.

Further, some embodiments of the system may include privacy controlswhich may be automatically implemented or controlled by the wearer ofthe device. For example, where a wearer's collected physiologicalparameter data and health state data are uploaded to a cloud computingnetwork for trend analysis by a clinician, the data may be treated inone or more ways before it is stored or used, so that personallyidentifiable information is removed. For example, a user's identity maybe treated so that no personally identifiable information can bedetermined for the user, or a user's geographic location may begeneralized where location information is obtained (such as to a city,ZIP code, or state level), so that a particular location of a usercannot be determined.

Additionally or alternatively, wearers of a device may be provided withan opportunity to control whether or how the device collects informationabout the wearer (e.g., information about a user's medical history,social actions or activities, profession, a user's preferences, or auser's current location), or to control how such information may beused. Thus, the wearer may have control over how information iscollected about him or her and used by a clinician or physician or otheruser of the data. For example, a wearer may elect that data, such ashealth state and physiological parameters, collected from his or herdevice may only be used for generating an individual baseline andrecommendations in response to collection and comparison of his or herown data and may not be used in generating a population baseline or foruse in population correlation studies.

FIG. 7 is a simplified block diagram illustrating the components of adevice 700, according to an example embodiment. Device 700 may take theform of or be similar to one of the wearable devices 100 a, 100 b, 100c, 100 d, 100 e, 100 f, 100 g, 100 h, 200, 300, 400, 500 shown in FIGS.1A-H, 2A-B, 3A-D, 4, and 5A-B. However, device 700 may also take otherforms, such as an ankle, waist, or chest-mounted device. Device 700could also take the form of a device that is not configured to bemounted to a body. For example, device 700 could take the form of ahandheld device configured to be maintained in proximity to anenvironment of interest (e.g., a body part, a biological samplecontainer, a volume of a water treatment system) by a user or operatorof the device 700 or by a frame or other supporting structure. Device700 also could take other forms.

In particular, FIG. 7 shows an example of a device 700 having a datacollection system 710 that includes two photodetectors 712, 714 and asensor 716, an actuator 750, a user interface 720, communicationinterface 730 for transmitting data to a remote system, A processor 740and a computer readable storage medium 760. The components of the device700 may be disposed on a mount or on some other structure for mountingthe device to enable stable detection of one or more properties of anenvironment of interest (e.g., of a body of a wearer of the device 700)and/or detection of the alignment of a target within the environment ofinterest, for example, to an external body surface where a portion ofsubsurface vasculature or other anatomical element (i.e., a target) isreadily observable.

Processor 740 may be a general-purpose processor or a special purposeprocessor (e.g., digital signal processors, application specificintegrated circuits, etc.). The one or more processors 740 can beconfigured to execute computer-readable program instructions 770 thatare stored in the computer readable medium 760 and that are executableto provide the functionality of a device 700 described herein.

The computer readable medium 760 may include or take the form of one ormore non-transitory, computer-readable storage media that can be read oraccessed by at least one processor 740. The one or morecomputer-readable storage media can include volatile and/or non-volatilestorage components, such as optical, magnetic, organic or other memoryor disc storage, which can be integrated in whole or in part with atleast one of the one or more processors 740. In some embodiments, thecomputer readable medium 760 can be implemented using a single physicaldevice (e.g., one optical, magnetic, organic or other memory or discstorage unit), while in other embodiments, the computer readable medium760 can be implemented using two or more physical devices.

Photodetectors 712, 714 could include any light-detecting componentsconfigured to detect the location, orientation, alignment, and/or someother information about the disposition of a target (e.g., a portion ofsubsurface vasculature) relative to one or more components (e.g., thephotodetectors 712, 714, the sensor 716) of the device 700. Sensor 716could include one or more components configured to detect one or moreproperties of an environment proximate to the sensor 716 (e.g., aportion of subsurface vasculature) and/or of energy or matter receivedfrom the proximate environment. As described above, the photodetectors712, 714 and the sensor 716 may include any component or componentscapable of detecting at least one property, which could include anyproperties that may relate to the alignment and/or some other propertyof the target and/or of the environment being analyzed by the device(e.g., the body of the wearer or a subsection thereof). For example, thesensor 716 could be configured to measure blood pressure, pulse rate,skin temperature, etc. In some examples, the photodetectors 712, 714and/or the sensor 716 may include one or more of an optical (e.g., CMOS,CCD, photodiode), acoustic (e.g., piezoelectric, piezoceramic),electrochemical (voltage, impedance), thermal, mechanical (e.g.,pressure, strain), magnetic, or electromagnetic (e.g., magneticresonance) sensor. In examples wherein the photodetectors 712, 714and/or the sensor 716 include a light sensor, the light sensor could bea photodiode, a photomultiplier, a CCD, a photocell, a photoresistiveelement, a camera, or any other sensor or sensors configured to detectone or more properties of light received from the target and/or anenvironment containing the target.

The photodetectors 712, 714 and/or the sensor 716 could additionallyinclude a light source or other energy emitter for transmittingillumination or other energy that can illuminate and/or penetrate theenvironment to illuminate, excite, or otherwise affect one or moreelements of interest on or in the target and/or the environmentcontaining the target. The wavelength of transmitted illumination couldbe specified to penetrate biological tissues of a wearer; for example,the transmitted illumination could have a wavelength within anear-infrared (NIR) transparency window of biological tissue. Thewavelength of the transmitted illumination could be specified to be awavelength that causes fluorescence and/or emission of light byfluorophores, chromophores, or other elements of interest. An energyemitter of the photodetectors 712, 714 and/or the sensor 716 could beconfigured to produce other forms of energy toward the environmentproximate to photodetectors 712, 714 and/or the sensor 716 that couldresult in emission, reflection, scattering or some other generation oflight or other energy or matter by other chemicals, imaging agents,biological elements, or other analytes proximate to the photodetectors712, 714 and/or the sensor 716.

Additionally or alternatively, the data collection system 710 couldinclude two or more light emitters and one or more photodetectorsconfigured to detect the alignment of a target relative to thephotodetector and/or light emitters as described herein. Such a datacollection system 710 could be further configured to detect one or moreproperties (e.g., a concentration of an analyte, an oxygen saturation)of the target and/or of the body of the wearer.

The actuator 750 could be any electrical and/or mechanical deviceconfigured to control the location of the data collection system 710and/or of individual elements (e.g., 712, 714, 716) of the datacollection system 710. The actuator 750 could include servos,piezoelectric elements, solenoids, motors, or other force-transducingelements.

The program instructions 770 stored on the computer readable medium 760may include instructions to perform any of the methods described herein.For instance, in the illustrated embodiment, program instructions 770include a controller module 772, calculation and decision module 774 andan alert module 776.

The controller module 772 can include instructions for operating thephotodetectors 712, 714 and/or the sensor 716. For example, thecontroller 772 may operate a light source and/or light sensors of thephotodetectors 712, 714 and/or the sensor 716 during each of a set ofpre-set measurement periods. The controller module 772 can furtherinclude instructions for operating the actuator 750 to control thelocation of the of the data collection system 710 and/or of individualelements (e.g., 712, 714, 716) of the data collection system 710. Forexample, the controller module 772 could include instructions to operatethe actuator 750 to control the location of one or more elements of thedata collection system 710 such that the one or more elements of thedata collection system 710 are aligned with a target. This operation ofthe actuator 750 could be performed responsive to an alignment of theone or more elements of the data collection system 710 relative to thetarget as detected by the photodetectors 712, 714.

The controller module 772 can also include instructions for operating auser interface 720. For example, controller module 772 may includeinstructions for displaying data collected by the data collection system710 and analyzed by the calculation and decision module 774, or fordisplaying one or more alerts generated by the alert module 776.Controller module 772 may include instructions for displaying datarelated to a detected alignment of one or more elements of the device700 such that a user could adjust the location and/or configuration ofthe device such that the one or more elements of the device 700 arealigned with the target. Further, controller module 772 may includeinstructions to execute certain functions based on inputs accepted bythe user interface 720, such as inputs accepted by one or more buttonsdisposed on the user interface.

Communication platform 730 may also be operated by instructions withinthe controller module 772, such as instructions for sending and/orreceiving information via a wireless antenna, which may be disposed onor in the device 700. The communication interface 730 can optionallyinclude one or more oscillators, mixers, frequency injectors, etc. tomodulate and/or demodulate information on a carrier frequency to betransmitted and/or received by the antenna. In some examples, the device700 is configured to indicate an output from the processor by modulatingan impedance of the antenna in a manner that is perceivable by a remoteserver or other remote computing device.

Calculation and decision module 774 may include instructions forreceiving data from the photodetectors 712, 714 and/or the sensor 716,analyzing the data to determine one or more properties of a target(e.g., the alignment of the target relative to one or more components ofthe device 700) and/or an environment containing the target (e.g., of abody of a wearer of the device 700), such as concentration of a targetanalyte, analyzing the data to determine if a medical condition or otherspecified condition is indicated, or other analytical processes relatingto the environment proximate to the device 700. In particular, thecalculation and decision module 774 may include instructions fordetermining, for each preset measurement time, the presence,concentration, and/or other properties of a clinically-relevant analytebased on information detected using the photodetectors 712, 714 and/orthe sensor 716; and determining whether a medical condition is indicatedbased on at least the corresponding presence, concentration, or otherproperty of the clinically-relevant analyte. These instructions could beexecuted at each of a set of preset measurement times.

The program instructions of the calculation and decision module 774 may,in some examples, be stored in a computer-readable medium and executedby a processor located external to the device 700. For example, thedevice 700 could be configured to collect certain data regardingphysiological parameters from the user and then transmit the data to aremote server, which may include a mobile device, a personal computer,the cloud, or any other remote system, for further processing.

The computer readable medium 760 may further contain other data orinformation, such as medical and health history of a user of the device700, that may be useful in determining whether a medical condition orsome other specified condition is indicated. Further, the computerreadable medium 760 may contain data corresponding to certainphysiological parameter baselines, above or below which a medicalcondition is indicated. The baselines may be pre-stored on the computerreadable medium 760, may be transmitted from a remote source, such as aremote server, or may be generated by the calculation and decisionmodule 774 itself. The calculation and decision module 774 may includeinstructions for generating individual baselines for the user of thedevice 700 based on data collected over a certain number of measurementperiods. Baselines may also be generated by a remote server andtransmitted to the device 700 via communication interface 730. Thecalculation and decision module 774 may also, upon determining that amedical or other emergency condition is indicated, generate one or morerecommendations for the user of the device 700 based, at least in part,on consultation of a clinical protocol. Such recommendations mayalternatively be generated by the remote server and transmitted to thedevice 700.

In some examples, the collected physiological parameter data, baselineprofiles, health state information input by device users and generatedrecommendations and clinical protocols may additionally be input to acloud network and be made available for download by a user's physician.Trend and other analyses may also be performed on the collected data,such as physiological parameter data and health state information, inthe cloud computing network and be made available for download byphysicians or clinicians.

Further, physiological parameter and health state data from individualsor populations of device users may be used by physicians or cliniciansin monitoring efficacy of a drug or other treatment. For example,high-density, real-time data may be collected from a population ofdevice users who are participating in a clinical study to assess thesafety and efficacy of a developmental drug or therapy. Such data mayalso be used on an individual level to assess a particular wearer'sresponse to a drug or therapy. Based on this data, a physician orclinician may be able to tailor a drug treatment to suit an individual'sneeds.

In response to a determination by the calculation and decision module774 that a medical or other specified condition is indicated, the alertmodule 776 may generate an alert via the user interface 720. The alertmay include a visual component, such as textual or graphical informationdisplayed on a display, an auditory component (e.g., an alarm sound),and/or tactile component (e.g., a vibration). The textual informationmay include one or more recommendations, such as a recommendation thatthe user of the device contact a medical professional, seek immediatemedical attention, or administer a medication.

III. Example Methods

FIG. 8 is a flowchart of a method 800 for operating a wearable device.The operated wearable device includes (i) at least light emitter, (ii)at least one photodetector, (iii) a mount configured to mount the atleast one light emitter and at least one photodetector to an externalbody surface proximate to a target, and (iv) a controller configured tooperate the at least one light emitter and the at least onephotodetector.

The method 800 includes mounting the wearable device to an external bodysurface using the mount (810). In some examples, the wearable devicecould be configured to be mounted to a wrist of a wearer (e.g., theembodiments illustrated in FIGS. 1A-1H, 2A-B, 3A-D, 4, and 5A-B) suchthat the at least one light emitter and at least one photodetector canbe operated to detect alignment of the target (e.g., a portion ofsubsurface vasculature) proximate to and/or within the wrist of thewearer. In some examples, the mount includes an adhesive, and mountingthe wearable device to the external body surface (810) includesactivating, applying, and/or exposing the adhesive and adhering thewearable device to the external body surface.

The method 800 also includes detecting, by the controller, alignment ofthe at least one light emitter and at least one photodetector relativeto the target (820). In some embodiments, detecting alignment of the atleast one light emitter and at least one photodetector relative to thetarget (820) could include operating the at least one light emitter andat least one photodetector to detect the location, orientation, or someother information about the disposition of the target. In someembodiments, the location of the target relative to the at least onelight emitter, at least one photodetector, and/or other components ofthe wearable device could be one of one or more specified locations,such that the target is aligned relative to element(s) of the wearabledevice. Thus, the at least one light emitter and at least onephotodetector could be operated as described above to detect thelocation, orientation, or some other information about the target and adetermination that the target is aligned could be made based on suchdetected information. Additionally or alternatively, the at least onelight emitter and at least one photodetector could be configured todetect some categorical and/or qualitative information about thealignment of the target. For example, the at least one light emitter andat least one photodetector could be configured to detect that thealignment of the target corresponds to one of a discrete set of states,e.g., ‘aligned,’ ‘nearly aligned,’ ‘not aligned,’ ‘not aligned in thedirection of a second photodetector of the at least one photodetector,’‘not aligned between a second and third light emitter of the at leastone light emitter,’ etc. That is, in some examples the disposition ofthe target relative to component(s) of the wearable device could be suchthat the target is not aligned, and detecting alignment of the at leastone light emitter and at least one photodetector relative to the target(820) could include making such a determination. Detecting alignment ofthe at least one light emitter and at least one photodetector relativeto the target (820) could include additional or alternative elementsand/or steps.

The method 800 for operating a wearable device could include additionalsteps relating to a detected alignment of a target and/or otherfunctions of the wearable device. In some examples, the wearable devicecould include a further sensors configured to detect a property of thetarget when the target is aligned relative to the at least one lightemitter, at least one photodetector, and/or the further sensor, and themethod 800 could include detecting the property of the target using thefurther sensor. Additionally or alternatively, one or morephotodetectors of the at least one photodetector could be configured todetect a property of the target when the target is aligned relative tothe one or more photodetectors, and the method 800 could includedetecting the property of the target using the one or morephotodetectors. This could include, responsive to the detection of thealignment of the at least one light emitter and at least onephotodetector, using the at least one photodetector to detect lightemitted from the target in response to light emitted by the at least onelight emitter. Further, one or more of the at least two photodetectorsand/or a further sensor could include an energy emitter and operatingthe at least two photodetectors and/or the further sensor to detectalignment or some other property of the target could include operatingthe energy emitter to emit some energy (e.g., visible light, infraredlight, ultraviolet light, an electromagnetic field, heat).

In some examples, the wearable device could include means to directly orindirectly effect the alignment of the at least one light emitter and atleast one photodetector with the target. In some examples, this couldinclude the wearable device including an actuator configured to controlthe location of the at least one light emitter and at least onephotodetector relative to the target. In such examples, the method 800could further include operating the actuator, relative to the detectedalignment of the target relative to the at least one light emitter andat least one photodetector at one or more points in time, to align theat least one light emitter and at least one photodetector with thetarget. In some examples, this could include the wearable deviceincluding an indicator (e.g., a display, a vibrator, a speaker, abuzzer, an electro-haptic stimulator) configured to convey someinformation about a detected alignment of the target relative to the atleast one light emitter and at least one photodetector. In suchexamples, the method 800 could further include indicating, using theindicator, information detected using the at least one light emitter andat least one photodetector such that a user of the wearable device(e.g., a wearer) can adjust the location of the at least one lightemitter, at least one photodetector, and/or other elements of thewearable device to align the at least one light emitter and at least onephotodetector relative to the target.

The example method 800 illustrated in FIG. 8 is meant as anillustrative, non-limiting example. Additional or alternative elementsof the method and additional or alternative components of the wearabledevice are anticipated, as will be obvious to one skilled in the art.

Conclusion

Where example embodiments involve information related to a person or adevice of a person, the embodiments should be understood to includeprivacy controls. Such privacy controls include, at least, anonymizationof device identifiers, transparency and user controls, includingfunctionality that would enable users to modify or delete informationrelating to the user's use of a product.

Further, in situations in where embodiments discussed herein collectpersonal information about users, or may make use of personalinformation, the users may be provided with an opportunity to controlwhether programs or features collect user information (e.g., informationabout a user's medical history, social network, social actions oractivities, profession, a user's preferences, or a user's currentlocation), or to control whether and/or how to receive content from thecontent server that may be more relevant to the user. In addition,certain data may be treated in one or more ways before it is stored orused, so that personally identifiable information is removed. Forexample, a user's identity may be treated so that no personallyidentifiable information can be determined for the user, or a user'sgeographic location may be generalized where location information isobtained (such as to a city, ZIP code, or state level), so that aparticular location of a user cannot be determined. Thus, the user mayhave control over how information is collected about the user and usedby a content server.

The particular arrangements shown in the Figures should not be viewed aslimiting. It should be understood that other embodiments may includemore or less of each element shown in a given Figure. Further, some ofthe illustrated elements may be combined or omitted. Yet further, anexemplary embodiment may include elements that are not illustrated inthe Figures.

Additionally, while various aspects and embodiments have been disclosedherein, other aspects and embodiments will be apparent to those skilledin the art. The various aspects and embodiments disclosed herein are forpurposes of illustration and are not intended to be limiting, with thetrue scope and spirit being indicated by the following claims. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the spirit or scope of the subject matter presentedherein. It will be readily understood that the aspects of the presentdisclosure, as generally described herein, and illustrated in thefigures, can be arranged, substituted, combined, separated, and designedin a wide variety of different configurations, all of which arecontemplated herein.

What is claimed is:
 1. A wearable device, comprising: at least twophotodetectors, wherein the at least two photodetectors are configuredto detect alignment of a target relative to the at least twophotodetectors; a mount configured to mount the at least twophotodetectors to an external body surface proximate to the target; anda controller configured to operate the at least two photodetectors todetect alignment of the target relative to the at least twophotodetectors.
 2. The wearable device of claim 1, wherein the externalbody surface is a wrist location.
 3. The wearable device of claim 1,wherein the target is a portion of subsurface vasculature.
 4. Thewearable device of claim 1, further comprising: an actuator, wherein theactuator is configured to control the location of the at least twophotodetectors relative to the target, and wherein the controller isconfigured to operate the actuator to align the at least twophotodetectors relative to the target.
 5. The wearable device of claim1, further comprising: a user interface, wherein the user interface isconfigured to indicate information relating to adjustment of thewearable device to align the at least two photodetectors relative to thetarget.
 6. The wearable device of claim 1, wherein detecting alignmentof the target relative to the at least two photodetectors comprisesdetecting the location of an alignment feature relative to the at leasttwo photodetectors.
 7. The wearable device of claim 1, wherein at leastone of the at least two photodetectors is configured to detect whetherthe wearable device is mounted to the external body surface, and whereinthe controller is configured to operate the at least one of the at leasttwo photodetectors to detect whether the wearable device is mounted tothe external body surface.
 8. The wearable device of claim 1, furthercomprising: a further sensor, wherein the further sensor is configuredto detect a property of the target when the at least two photodetectorsare aligned relative to the target, wherein alignment of the targetrelative to the at least two photodetectors comprises alignment of thefurther sensor relative to the target, and wherein the controller isfurther configured to operate the further sensor to detect the propertyof the target in response to detecting that the at least twophotodetectors are aligned relative to the target.
 9. The wearabledevice of claim 8, wherein the further sensor comprises an energyemitter, and wherein alignment of the further sensor relative to thetarget comprises alignment of the energy emitter relative to the target.10. A wearable device, comprising: at least two light emitters, whereinthe at least two light emitters are configured to illuminate a target;at least one photodetector, wherein the at least one photodetector isconfigured to detect alignment of a target relative to the at least onephotodetector by detecting light emitted from the target in response toillumination by the at least two light emitters; a mount configured tomount the at least two light emitters and at least one photodetector toan external body surface proximate to the target; and a controllerconfigured to operate the at least two light emitters and at least onephotodetector to detect alignment of the target relative to the at leastone photodetector.
 11. The wearable device of claim 10, wherein the atleast one photodetector is configured to detect a property of the targetwhen the at least one photodetector is aligned relative to the target,and wherein the controller is further configured to operate the at leastone photodetector to detect the property of the target in response todetecting that the at least one photodetector is aligned relative to thetarget.
 12. The wearable device of claim 10, further comprising: anactuator, wherein the actuator is configured to control the location ofthe at least two light emitters and the at least one photodetectorrelative to the target, and wherein the controller is configured tooperate the actuator to align the at least one photodetector relative tothe target.
 13. The wearable device of claim 10, further comprising: auser interface, wherein the user interface is configured to indicateinformation relating to adjustment of the wearable device to align theat least one photodetector relative to the target.
 14. The wearabledevice of claim 10, wherein the at least two light emitters are arrangedas a linear array.
 15. A method, comprising: mounting a wearable deviceto an external body surface, wherein the wearable device comprises: (i)at least one light emitter, (ii) at least one photodetector, (iii) amount configured to mount the at least one light emitter and at leastone photodetector to an external body surface proximate to a target, and(iv) a controller configured to operate the at least one light emitterand at least one photodetector; and detecting, by the controller, analignment of the at least one light emitter and at least onephotodetector relative to the target.
 16. The method of claim 15,further comprising: responsive to detecting the alignment of the atleast one light emitter and at least one photodetector relative to thetarget: emitting, by the at least one light emitter, light toward thetarget via the external body surface; and detecting, by the at least onephotodetector, light emitted from the target via the external bodysurface in response to the light emitted by the at least one lightemitter.
 17. The method of claim 16, further comprising: determining atleast one property of the target based on the light emitted from thetarget and detected by the at least one photodetector.
 18. The method ofclaim 15, wherein the at least one light emitter comprises a pluralityof light emitters, and wherein detecting the alignment of the at leastone light emitter and at least one photodetector relative to the targetcomprises detecting that a particular light emitter in the plurality oflight emitters and the at least one photodetector are aligned relativeto the target.
 19. The method of claim 15, wherein the at least onephotodetector comprises a plurality of photodetectors, and whereindetecting the alignment of the at least one light emitter and at leastone photodetector relative to the target comprises detecting that aparticular photodetector in the plurality of photodetectors and the atleast one light emitter are aligned relative to the target.
 20. Themethod of claim 15, wherein the wearable device further comprises a userinterface, and further comprising: indicating, using the user interface,information related to adjustment of the wearable device to align the atleast one light emitter and at least one photodetector relative to thetarget.